the genetics of fh in saudi arabia: data from the fh … · 2020-02-13 · the genetics of fh in...

THE GENETICS OF FH IN SAUDI ARABIA:

DATA FROM THE FH GULF REGISTRY

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Dr. Faisal A. Al-AllafProfessor of Genetics and Molecular MedicineDepartment of Medical GeneticsFaculty of MedicineUmm Al-Qura University Makkah, Saudi Arabia [email protected]: 012 52 70000 Ext 4198 or 4197

FAMILIAL HYPERCHOLESTEROLAEMIA IN THE MENA REGION:

DO WE HAVE THE DATA

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Familial hypercholesterolemia (FH)

Coronary artery diseases (CAD) inflict heavy economical and social cost on mostpopulations and contribute significantly to their morbidity and mortality rates.

FH is hereditary disease, usually under diagnosed and is a major risk factor for thedevelopment of CAD.

Approximately, half of the heterozygous men with FH, if untreated, will developclinically evident CAD by the age of 55 years.

Affected heterozygous women from the same families typically develop CAD about 9years later than their affected male relatives.

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Epidemiological genetic studies

In the majority of populations, the heterozygote form occurs in less than 1:500 and the homozygous form isone in one million.

However, recent studies have changed this perception and shown that FH is under diagnosed in mostpopulations.

HeFH prevalence according to DLCN criteria may reach 1 in every 200 individuals. Consequently, HoFH mayrise to one in every 300,000 individuals.

The highest frequency of heterozygosity with an incidence of less than 1:80 is found in the Afrikanerpopulation in South Africa.

Studies on the French Canadian population where five common mutations are known, show a frequency of1:270.

This unusual high frequency is due to founder effects and consanguinity.

Because of the AD mode of inheritance the heterozygous are affected and therefore FH is the most frequentMendelian disorder being more frequent than homozygous CF and sickle cell anaemia.

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The incidence of FH is not known in the Middle East

We are not aware of any epidemiological genetic study examining the frequency of FH in MENApopulation.

The high incidence of consanguinity marriages which exceeding 54% in Saudi population and theoccurrence of many cardiovascular centres across the country, suggesting that the incidence might be high.

We estimated that at least 63,485 (this number can be as high as 158,712) Saudis are affected.(http://www.stats.gov.sa/en/node).

Because the disease is asymptomatic, the majority of patients may not be aware of their illness until asevere myocardial infarction, which often leads to sudden death or other cardiovascular events occur inthe fourth or fifth decade of life.

http://www.stats.gov.sa/en/node)

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Clinical manifestation of FHMeasurement of blood cholesterol levels are NOT sufficient to confirm a diagnosis of FH

The range of blood cholesterol levels in FH overlaps with that of people with non-genetic multifactorialhypercholesterolaemia, which may lead to a false positive or false negative diagnosis

Diagnostic Criteria from

◦ The Simon Broome Register Group. BMJ. OCT 12 1991

◦ The Dutch Lipid Clinic Network (The Netherlands). Nordestgaard et al. Eur Heart J. 2013

◦ The MEDPED criteria (USA).

◦ The European guidelines. Cuchel et al. Eur Heart J. 2014.

All suggest that diagnosis can be made on the basis of Laboratory finding, physical signs,family history (a dominant pattern of inheritance for either premature CAD orhypercholesterolaemia) and, where available, genetic confirmation.

Autosomal Dominant FH

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LDLR (the plasma membrane Low Density

Lipoprotein Receptor)

ApoB (Apolipoprotein B 100)

PCSK9 (the neural apoptosis regulated convertase 1)

Autosomal Recessive FH

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LDLRAP1 (the plasma

membrane Low Density

Lipoprotein Receptor

Adaptor Protein 1)

Classes of LDLR mutations and genotype/phenotype correlation

The null receptor phenotype results fromnon-sense mutation(s) or deletion(s) in thepromoter region within the LDLR gene

The transport deficient receptors aresynthesised normally in the endoplasmicreticulum but fail to be transported to theGolgi apparatus for further processing

Binding deficient LDLR is transportednormally to the cell membrane but bindsLDL only partially

The internalisation defective receptorsreach the cell surface and bind LDL, butfail to cluster in clathrin coated pits

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Causative Mutations

• Loss of Function Mutations

LDLR

Accounts for 85-90%.Over 1000 mutations reported

No hotspots in some population

ApoB

Accounts for 1-5%Only two mutations is reported

• Gain of Function Mutations

PCSK9

Account for 5-10%Nine mutations are reported

Other candidate Genes: ABCA1, APOA2, APOC3, PON2, ARH, LDLRAP1, APOC2, APOE, and LPL

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MOROCO

FH-Moroco-1, El Messal et al., 2003


c.682G>T, p.(E228*), Hobbs et al., 1992

c.400T>C, p.(C134R), El Messal et al., 2003

c.859G>T, p.(G287C), El Messal et al., 2003

c. 1171G>A, p.(A391T), El Messal et al., 2003

c. 2054C>T, p.(P685L), El Messal et al., 2003

c. 2132C>T, p.(C711S), El Messal et al., 2003

c.138C>A, p.(C46*), Chater et al., 2006

c.313+5G>T, Chater et al., 2006

c.1736A>C, p.(D579A), Chater et al., 2006

c.514G>A, p.(D172N), Chater et al., 2006

c.1502C>A, p.(A501E), Chater et al., 2006

c.756_762delCCGGCAG, Chihab et al., 2007

ALGERIA

c.1222G>A, p.(E408K) (FH Algeria-1), Hobbs et al. 1992

c.1291G>A, p.(A431T) (FH Algeria-2), Hobbs et al. 1990

c.1301C>A, p.(T434K) (FH Algeria-3), Hobbs et al. 1992

TUNIS

c.1477_1479delTCTinsAGAGACA, p.(S493Rfs*44) (FH-Souassi), Slimane et al., 2001

LEBANON

c.2043C>A, p.(C681*), Lehrman et al. 1987

c.406C>T, p.(Q136*), Garcia et al., 2001

c.[605C>A, p.(P202H), Garcia et al., 2001

748-608G>A, (W249ins62*), Wilund et al 2002

c.89-1G>C, p.(K30T*3), Lind et al., 2004

SYRIA

c.550T>C, p.(C184R), Hobbs et al. 1992

c.827G>A, p.( C276Y), Vergopoulos et al. 1998

c.1027G>A, p.(G343S), Vergopoulos et al. 1998

c.1172del1, p.(A370fs), Reshef et al., 1996

c.2043C>A, p.(C681*), Vergopoulos et al. 1998

c.1999T>C, p.(C667R), Lehrman et al. 1987

c.2483A>G, p.(Y828C), Vergopoulos et al 1997

c.89-1G>C, p.(K30T*3), Al-Kateb et al., 2002

SAUDI ARABIA

c.2439G>A, p.(W813*), Lehrman et al., 1985

BAHRAIN


LDLR = WHITE, ApoB100 = BLUE , PCSK9 = YELLOW, LDLRAP1 = RED 11

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Points strongly support the need for national genetic screening program and the potential benefits

The vast majority may not be aware of the inherited nature of their illness.

◦ >63,000 (this number can be as high as 158,712) Saudis are affected

Genetic testing using molecular method are the most accurate way of diagnosing FH, especially at thecrucial prenatal age

The spectrum of mutations causing FH in Saudis is not known

Once the mutations will be identified, the cost of the genetic diagnosis will also drop an order ofmagnitude because the testing will be targeted to the defective part of the gene

Genetic counselling can be offered to the affected family members especially for the prevention of theoccurrence of homozygotes patients resulting for consanguineous marriages of heterozygote patients

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2011

2012

14DR. FAISAL AL-ALLAF, [email protected]

2013

http://www.fh-sa.com

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http://www.fh-sa.com/

Selection criteria: Simon Broome Criteria

‘Definite’ FH – A+B must be present

‘Possible’ FH – A+C or A+D

A. Total and LDL-Cholesterol16 years+ : Total cholesterol >7.5mmol/l

(>290mg/dl) or LDL-C >4.9mmol/l (>190mg/dl)

Under 16 years: Total cholesterol >6.7mmol/l (>260mg/dl) or LDL-C >4.0mmol/l (>155mg/dl)

B. Tendon xanthomas in patient or 1st (parents, sibling, children) or 2nd (grandparents, uncle, aunt) degree relative

C. FH of myocardial infarction (MI) <60 yrsin 1st degree relative or FH of MI <50 yrs in 2nd degree relative

D. FH of total cholesterol >7.5mmol/l (>290mg/dl) in 1st or 2nd degree relative 16

←

←

←

Selection criteria: Simon Broome Criteria

‘Definite’ FH – A+B must be present

‘Possible’ FH – A+C or A+D

A. Total and LDL-Cholesterol16 years+ : Total cholesterol >7.5mmol/l

(>290mg/dl) or LDL-C >4.9mmol/l (>190mg/dl)

Under 16 years: Total cholesterol >6.7mmol/l (>260mg/dl) or LDL-C >4.0mmol/l (>155mg/dl)

B. Tendon xanthomas in patient or 1st (parents, sibling, children) or 2nd (grandparents, uncle, aunt) degree relative

C. FH of myocardial infarction (MI) <60 yrsin 1st degree relative or FH of MI <50 yrs in 2nd degree relative

D. FH of total cholesterol >7.5mmol/l (>290mg/dl) in 1st or 2nd degree relative

H) Left Anterior Descending (LAD): mid segment significant lesion (red arrow). I) Left Anterior

Descending (LAD): post PCI and stent (red arrow). J) Right Coronary Artery totally occluded proximally.

K) Right Coronary Artery (RCA): post PCI and stent (red arrow).17

Genetic Diversity of FH

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Homozygous

Heterozygous

DoubleHeterozygous

CompoundHeterozygous

Familial Hypercholesterolemia mutation detection Algorithm

Clinical suspicion of autosomal dominant hypercholesterolemia according to Simon Broome criteria

APOB genotype a is performed for the common APOB 100 mutations R3500Q and R3500W

No APOB mutations detectedLDLR gene sequencing b is performed

APOB mutation(s) detected Interpretive report is provided

Consider testing at-risk relatives for the familial mutation(s)

LDLR gene mutation(s) detected by sequencing.Interpretive report is provided

No LDLR gene mutations detected by sequencing. LDLR large deletion/duplication analysts c performed using MLPA


No LDLR large deletion or duplication mutations detected. PCSK9 mutation analysis or NGS analysis using Ion torrent custom made chips

LDLR large deletion or duplication mutation(s) detected. Interpretive report provided.

Consider testing at-risk relatives for the familial mutation(s) LDLR gene mutation(s) detected by NGS.

Mutation(s) re confirmed by capillary sequencing. Interpretive report is provided


PCSK9 gene mutation(s) detected by capillary sequencing.Interpretive report is provided


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Identification of Novel nonsense mutation p.D445X in LDLR gene causes familial hypercholesterolemia

We have identified a novel insertion mutation (c.1332_1333insT) at exon 9 of the LDLR gene (alr family)

This insertion mutation results in a premature stop codon at position 445 in exon 9 of the LDLR gene, which results in truncation of the protein.

Development of NextGeneration Sequencingchip to Identify GeneticVariants Causative of FH

Ldlr, ApoB, Pcsk9, Abca1, Apoa2, Apoc3, Apon2, Arh, Ldlrrap1, Apoc2, ApoE, and Lpl

LDLR Exon 14 (c.2026delG, p. Gly676Fs), Novel mutation)Glycine – Alanine

Identification of anovel causative frameshift mutation at theLDLR Exon 14(c.2027delG, p.Gly676fs)

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Compound heterozygousmutation withmissense/frameshift DNAsequence variants in theLDLR in Saudi patientssuffering severhypercholesterolemia

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Regular paper

Compound heterozygous LDLR variant in severely af ected familial hypercholesterolemia patient

Faisal A. Al-Allaf1,2,3#*, Abdullah Alashwal4#, Zainularifeen Abduljaleel1,2,

Mohiuddin M. Taher1,2, Abdellatif Bouazzaoui1,2, Hala Abalkhail4, Ahmad F. Al-Allaf5 and Mohammad Athar1,2#*

1Department of Medical Genetics, Faculty of Medicine, Umm Al-Qura University, Makkah, Saudi Arabia; 2Science and Technology Unit, Umm Al-Qura University, Makkah, Saudi Arabia; 3Molecular Diagnostics Unit, Department of Laboratory and Blood Bank, King Abdullah Medical City, Makkah, Saudi Arabia; 4King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia; 5Faculty of Medicine, Alfaisal University, Riyadh, Saudi Arabia

Familial hypercholesterolemia (FH) is most commonly caused by mutations in the LDL receptor (LDLR), which is responsible for hepatic clearance of LDL from the blood circulation. We described a severely af ected FH proband and their f rst-degree blood relatives; the proband was resistant to statin therapy and was managed on an LDL apheresis program. In order to f nd the causative ge-netic variant in this family, direct exon sequencing of the LDLR, APOB and PCSK9 genes was performed. We identi-f ed a compound heterozygous mutation in the proband with missense p.(W577C) and frameshift p.(G676Afs*33) variants at exons 12 and 14 of the LDLR gene respec-tively. DNA sequencing of LDLR gene from the parents demonstrated that the missense variant was inherited from the mother and frameshift variant was inherited from the father. The frameshift variant resulted in a stop signal 33 codons downstream of the deletion, which most likely led to a truncated protein that lacks impor-tant functional domains, including the trans-membrane domain and the cytoplasmic tail domain. The missense variant is also predicted to be likely pathogenic and af-fect EGF-precursor homology domain of the LDLR pro-tein. The segregation pattern of the variants was consist-ent with the lipid prof le, suggesting a more severe FH phenotype when the variants are in the compound hete-rozygous state. The f nding of a compound heterozygous mutation causing severe FH phenotype is important for the genotype-phenotype correlation and also enlarges the spectrum of FH-causative LDLR variants in the Arab population, including the Saudi population.

Key words: familial hypercholesterolemia (FH), low-density lipopro-tein receptor (LDLR), compound heterozygous, missense variant, frameshift variant, sequencing, Arab, coronary artery disease (CAD), cholesterol, genetics

Received: 05 March, 2016; revised: 23 June, 2016; accepted: 04 October, 2016; available on-line: 23 November, 2016

*e-mail: [email protected] (FAAl-A); [email protected], mab-

[email protected] (MA)#Authors contributed equally to the manuscriptAbbreviations: CAD, Coronary artery disease; CHD, Coronary heart diseases; FH, Familial hypercholesterolemia; LDLR, low-density lipo-protein receptor; APOB, apolipoprotein B; PCSK9, Pro-protein con-vertase subtilisin/kexin type 9; DNA, Deoxyribonucleic acid; LDL, low-density lipoprotein; LDL-C, low-density lipoprotein-cholesterol; HDL, High-density lipoprotein; HDL-C, High-density-lipoprotein-cholesterol; TC, Total cholesterol; TG, Triglycerides; EDTA, Ethylen-ediaminetetraacetic acid; PCR, Polymerase chain reaction; EGF, Epi-dermal growth factor.

INTRODUCTION

Coronary heart diseases (CHD) inflic t heavy economi-cal and social cost on most populations including Saudis and contribute significa nt ly to their morbidity and mor-tality rates. Familial hypercholesterolemia (FH) is heredi-tary in an autosomal dominant manner and is a major risk factor for the development of CHD (Cuchel et al., 2014). If untreated, persistent hypercholesterolemia may produce tendon xanthomata (Achilles, extensor tendons of hands and feet), cutaneous planar, corneal arcus and premature cardiovascular disease (Al-Allaf et al., 2015). Because the disease is initially asymptomatic and pain-less, the majority of patients may not be aware of their illness until a severe myocardial infarction occurrs in the fourth or fift h decade of life due to instant atheroma, which often leads to sudden cardiac death or other se-vere cardiovascular events (Al-Allaf et al., 2010). FH is most commonly caused by mutations in the LDL recep-tor (LDLR), which is responsible for hepatic clearance of low-density lipoprotein (LDL) from the blood circu-lation. FH can also be caused by certain mutations in the apolipoprotein B (APOB) gene, which encodes the ligand for LDLR (Yang et al., 2007). The pro-protein convertase subtilisin/kexin type 9 (PCSK9) gene was considered the third gene with pathogenic mutations accounting for some FH cases (Abifadel et al., 2003; Timms et al., 2004).

More than 1700 different variants of the LDLR gene were found to cause familial hypercholesterolemia (www.ucl.ac.uk/ldlr), making genetic screening very laborious. Mutations in the LDLR gene were divided into five classes based on biochemical and functional studies on LDLR variants; such that Class 1 mutations include null alleles that lack any LDLR protein product. Class 2 mu-tations encode LDL receptor (LDLR) proteins that are abnormally transported from the endoplasmic reticulum to the Golgi apparatus. In Class 3 mutations, LDLR protein shows defective binding of the LDL ligand, and Class 4 mutation genes encode LDLR with disrupted in-ternalization/endocytosis of LDL. Class 5 mutations in the LDLR gene encode LDLR which displays defective recycling (Jeon et al., 2005).

To date there is no cure for FH. The primary goal of clinical management in severely affected patients is to control hypercholesterolemia in order to decrease the risk of atherosclerosis and to prevent CHD. The most common cholesterol-lowering agents are statin and its derivatives. Treatment with non-statin cholesterol lower-

Vol. 64, No 1/201775–79

https://doi.org/10.18388/abp.2016_1283

Identification andtreatment ofpatients withhomozygous FH

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4 Current Vascular Pharmacology, 2015, Vol. 13, No. 6 Al-Ashwal et al.

Although genetic testing may provide a definitive diag-nosis of HoFH, in some patients extensive testing may fail to yield genetic confirmation [6, 7]. This is because up to 20% of clinically defined FH patients will have a mutation that has not yet been identified [24]. HoFH is most commonly caused by mutations in both alleles of the LDLR gene, in individuals with parents who each have heterozygous FH. However, recently, mutations in genes coding for apo B, PCSK9 and LDL receptor adapter protein 1 (LDLRAP1), have been identified as causal in some patients with a severe phenotype resembling HoFH [8, 13, 25].

HoFH patients may be ‘true homozygotes’, with the same

mutation in both alleles of the same gene, or ‘compound

heterozygotes’ with different mutations in the two alleles of

the same gene. Patients may also carry mutations in two dif-

ferent genes affecting LDL receptor function (Fig. 3). The

severity of the mutation is a major factor governing the se-

verity of the phenotype. Patients with mutations resulting in

defective LDL-R usually have less elevated LDL-C than

patients with mutations resulting in a complete absence of

LDL-R activity [8]. Generally, the pattern of mean LDL-C

levels by genotype increase as follows: HeFH < double het-

erozygote (e.g. LDL+PCSK9 gain-of-function or apo B mu-

tation) < homozygous apo B or PCSK9 gain-of-function mu-

tation < homozygous LDLRAP1 or LDLR-defective muta-

tions < compound heterozygote LDLR-defective+LDLR-

negative mutations < homozygous LDLR-negative mutations [8].

However, there is considerable overlap in the observed

untreated LDL-C levels according to genotype [10], so an

individual compound heterozygote for LDLR, for example,

may have very severe hypercholesterolaemia, and equally, a

simple LDLR homozygote may have lower untreated LDL-C

levels. In many instances, a patient with a negative genetic

test for HoFH may still have homozygous mutations, but

these mutations have not been identified within the current

panel of known HoFH-associated mutations. Therefore, if

the spectrum of mutations causing FH in a certain population

is not known/identified, genetic testing, while valuable, can-

not yet be considered a 100% reliable means of identifying

HoFH patients in such patients. Next-generation sequencing techniques may alleviate or eradicate this limitation.

Genetic testing, where available still needs to be accom-panied by comprehensive clinical and family history profiles [24]. A positive genetic test is definitive for HoFH. It is pos-sible that cascade testing in the immediate family of an index patient may be made easier if the index mutation is known, and if the most common mutations in the Middle East region could be profiled.

Another disorder of lipid metabolism, sitosterolaemia (or phytosterolaemia), may have a similar clinical presentation to HoFH. A definitive diagnosis of sitosterolaemia can be confirmed by genetic analysis. In common with HoFH, any genetically determined metabolic disorder is likely to be more common in regions with lower genetic admixture than those with very few consanguineous marriages [26].

Summary and Recommendations

Our recommendations for diagnosis of HoFH are similar to those set out in the European guidelines (Table 1) [8].

· HoFH can be suspected if LDL-C levels are

>13 mmol/L (500 mg/dL) in untreated patients, or >8 mmol/L (300 mg/dL) in treated patients.

· Confirmation of diagnosis can be made if the elevated

LDL-C is accompanied by either cutaneous or tendon

xanthomas before the age of 10 years, or untreated

elevated LDL-C levels consistent with HeFH in both parents.

· Genetic testing can independently confirm the diagnosis

of HoFH, but a negative result does not rule out the pos-sibility of FH.

· Detection rates for HoFH in the Middle East are low,

and efforts must be made by the preventative cardiology

and lipidology communities to educate dermatologists,

general practitioners, plastic surgeons and cardiologists on the true prevalence and recognition of the disease.

· Genetic counselling should be given to couples where

there is a risk of HoFH in their offspring, and patients

should be advised to limit the number of pregnancies for

reasons of both genetic transmission and maternal car-

diovascular risk. Hormonal contraception should be avoided [8].

Fig. (2). Tendon xanthomas characteristic of homozygous familial hypercholesterolaemia (HoFH)

Cutaneous and tuberous xanthomas in homozygous familial hypercholesterolaemia. Original photographs by Prof. Eric Bruckert and Prof.

Frederick Raal. Reproduced from Cuchel et al. Eur Heart J 2014;35:2146-57 [8] under the terms of the Creative Commons Attribution Non-

Commercial License (http://creativecommons.org/licenses/by-nc/4.0/).

Investigate the Structuraland Functional Attributes of Familial Hypercholesterolemia Variants

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The Spectrum of Familial Hypercholesterolemia (FH) in Saudi Arabia: Prime Time for Patient FH Registry

23

5

A

1\500

1\200

0 5000

Expecte

63,485

158,7

00 100000

ed HeFH cases

712

0 150000

B

1\600

1\300

0

0,000

0,000

Expe

53

50

ected HoFH cas

106

100 15

ses

50

A

1\500

1\200

0 5000

Expecte

63,485

158,7

00 100000

ed HeFH cases

712

0 150000

B

1\600

1\300

0

0,000

0,000

Expe

53

50

ected HoFH cas

106

100 15

ses

50

Novel combined variants of LDLR and LDLRAP1 genes causing severe familial hypercholesterolemia

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MOROCO



c.682G>T, p.(E228*), Hobbs et al., 1992












ALGERIA




TUNIS


LEBANON





c.89-1G>C, p.(K30T*3), Lind et al., 2004

SYRIA









SAUDI ARABIA


BAHRAIN


LDLR = WHITE, ApoB100 = BLUE , PCSK9 = YELLOW, LDLRAP1 = RED 28

MOROCO

c.682G>T, p.(E228*), Hobbs et al., 1992














ALGERIA




TUNIS


c.1186+1G>A, p.(E380_G396), Jelassi et al., 2008

c.1845+1G>A(FH-Tunis), Jelassi et al., 2009

c.267C>G, p.C89W, Jelassi et al., 2009

C.443G>C, p.(C148S), Jelassi et al., 2009

C.796G>A , p.(D266N), Jelassi et al., 2009

C.1027G>T, p.(G343C), Jelassi et al., 2009

c.2446A>T, p.(K816*), Slimani et al., 2009

c. c.1545T>G, p.(F515L), Jelassi et al., 2011

c.2009A>G, p.(G670E), Jelassi et al., 2011

2299delA, p.(M767Cfs*21), Jelassi et al., 2012

12684 bp del (ex2-5), Jelassi et al., 2012

2364 bp del (ex5-6), Jelassi et al., 2012

c.520C > T, p.(P174S), Jelassi et al., 2012

LEBANON





c.89-1G>C, p.(K30T*3), Lind et al., 2004

c.761A>C, p.(Q254P), Abifadel et al., 2009

c.1066G>T, p.(D356Y), Abifadel et al., 2009

c.1073G>A, p.(C358Y), Abifadel et al., 2009

c.1329G>A, p.(W443*), Abifadel et al., 2009

c.1352T>G, p.(I451T), Abifadel et al., 2009

c.2476C>T, p.(P826S), Abifadel et al., 2009

c.1171G>A, p.(A391T), Fahed et al., 2011

SYRIA









BAHRAIN


c.1706-2A>T in SA site of intron 11, Shawar et al., 2012

OMAN

c.272delG, Al-Hinai et al., 2013

p.(V474I), Al-Waili et al., 2013

29LDLR APOB PCSK9 LDLRAP1 ABCA1 PON2 LPL APOC3

SAUDI ARABIAc.2439G>A, p.(W813*), Lehrman et al., 1985

c.1332dup, p.(D445*), Al-Allaf et al., HGV, 2014

c.2026delG, p.(G676Afs*33), Al-Allaf et al., Gene, 2015

c.2027delG, p.(G676Afs*33), Al-Allaf et al., Genomics, 2015

c.313C>T, p.(P105S), Alharbi et al., 2015

c.1171G>A, p.(A391T), Alharbi et al., 2015

c.1731G>T, p.(W577C), Al-Allaf et al., ABP, 2017

c.2416dupG, p.(V806Gfs*11), Al-Allaf et al., OCMJ, 2017

c.185C>T, p.(T62M), Al-Allaf et al., OCMJ, 2017

c.622G>A, p.(E208K), Al-Allaf et al., OCMJ, 2017

c.1474G>A, p.(D492N), Al-Allaf et al., OCMJ, 2017

c.1429G>A, p.(D477N), Al-Allaf et al., OCMJ, 2017

c.1783C>T, p.(R595W), Al-Allaf et al., OCMJ, 2017

c.1706-2A>T in SA site of intron 11, Al-Allaf et al., OCMJ, 2017

c.1255T>G, p.(Y419D), Alnouri et al., Atherosclerosis, 2018

c.335_336insCGAG, p.(D112fs*19), Al-Allaf et al., 2018 (Submitted)

c.666_670dup, p.(Asp224Alafs*43), Al-Allaf et al., 2018 (Submitted)

c.1301C>A, p.(T434K), Al-Allaf et al., 2018 (Submitted)

c.1313A>G, p.(D438G), Al-Allaf et al., 2018 (Submitted)

c.9835A>G, p.(S3279G), Morad et al., JOCB, 2017

c.8216C>T, p.(P2739L), Al-Allaf et al., 2018 (Submitted)

c.5768A>G, p.(H1923R), Al-Allaf et al., 2018 (Submitted)

c.433C>T, p.(P145S), Al-Allaf et al., 2018 (Submitted)

c.1853C>T, p.(A618V), Al-Allaf et al., 2018 (Submitted)

c.3634C>A, p.(L1212M), Al-Allaf et al., 2018 (Submitted)

c.5741A>G, p.(N1914S), Al-Allaf et al., 2018 (Submitted)

c.9937C>A, p.(L3313I), Al-Allaf et al., 2018 (Submitted)

c.158C>T, p.(A53V), Morad et al., JOCB, 2017

c.1658A>G, p.(H553R), Al-Allaf et al., 2018 (Submitted)

c.658-7C>T, Al-Allaf et al., 2018 (Submitted)

c.799+3A>G, Al-Allaf et al., 2018 (Submitted)

c.799+26 C>T, Al-Allaf et al., 2018 (Submitted)

c.547_548insA, p.(G183fs), Al-Allaf et al., 2018 (Submitted)

c.988G>C, p.(A330P), Al-Allaf et al., 2018 (Submitted)

c.604_605delTCinsA, p.(S202Tfs*2), Alnouri et al., Atherosclerosis, 2018

c.811G>A, p.(V271I), Al-Allaf et al., 2018 (Submitted)

c.712C>T, p.(R238W), Al-Allaf et al., 2018 (Submitted)

c.2328G>C, p.(K776N), Al-Allaf et al., 2018 (Submitted)

c.896C>G, p.(S299C), Al-Allaf et al., 2018 (Submitted)

c.407C>G, p.(A136G), Al-Allaf et al., 2018 (Submitted)

c.932C>G, p.(S311C), Al-Allaf et al., 2018 (Submitted)

c.443C>G, p.(A148G), Al-Allaf et al., 2018 (Submitted)

c.248G>A, p.(G83E), Al-Allaf et al., 2018 (Submitted)

c.1421C>G, p.(S474*) , Al-Allaf et al., 2018 (Submitted)

c.106G>A, p.(D36N) , Al-Allaf et al., 2018 (Submitted)

c.55C>T, p.(R19*), Al-Allaf et al., 2018 (Submitted)

30

Novel

mutationsPublication Conferences

Knowledge

Transfer

Technology

TransferEcho System

Impact on

Health

Impact on

Community

Impact on

Economy

88 10 √ √ √ √ √√

31

Sttering committee Affiliation Country

Dr.Wael Almahmeed Heart and Vascular Institute -Cleveland Clinic, Abu

Dhabi

United Arab Emirates

Dr. Abdullah Shehab UAE University, College of Medicine & Health Sciences United Arab Emirates

Dr.Faisal Al-Allaf Department of Medical Genetics, Faculty of Medicine,

Umm Al-Qura University, Makkah

Saudi Arabia

Dr.Fahad Al Noori Prince Sultan Cardiac Center, Riyadh Saudi Arabia

Dr.Hussam Alfaleh King Fahad cardiac Center, College of Medicine, King

Saud University, Riyadh

Saudi Arabia

Dr.Zuhair Awan King Abdulaziz University and King Fahad Institute of

Research.

Saudi Arabia

Dr .Abdulhalim Kensara National Guard Hospital, Jeddah Saudi Arabia

Dr.Khalid Al-Waili Biochemistry, Sultan Qaboos University Hospital,

Muscat

Oman

Dr.Fahad Al-Zadjali Biochemistry, College of Medicine & Health Science,

Sultan Qaboos University, Muscat

Oman

Dr.Ibrahim Al-Zakwani Department of Pharmacology & Clinical Pharmacy,

College of Medicine & Health Sciences, Sultan Qaboos

University, Muscat

Oman

Dr.Nasreen AlSayed Gulf Diabetes Specialist Center, Manama Bahrain

Dr. Haitham Amin Bahrain

Dr. Ahmed Al-Sarraf Laboratory Department, Kuwait Cancer Control Center Kuwait

Dr Mohammed Al-Jarallah Head of Sabah Al-Ahmed

Cardiac Center

Kuwait

Dr. Nidal Asaad Qatar Heart Hospital, Hamad Medical corporation Qatar

Prof.Peter Lansberg Coordinator Durrer Center for Cardiogenetic Research Netherland

Lead Investigators Khalid F. AlHabib

Khalid Al Rasadi

Project Manager Hani Altaradi

Gulf FH Registry and Genetics Testing

32

Gulf Registry (eCRF)

Familial/Autosomal Dominant Hypercholesterolemia mutation detection Algorithm

ClinicalsuspicionofautosomaldominanthypercholesterolemiaaccordingtoSimonBroomecriteria

LDLRgenesequencing(Capillary;Sanger)isperformedforthecommontribesassociatedmutationspanel/hotspot

LDLRgenemutation(s)detectedbysequencing.Interpretivereportisprovided

NoLDLRgenemutationsdetectedbysequencing.NGS(Iontorrent)analysisforcustomizedFHassociatedgenes(LDLR, APOB, PCSK9 and LDLRAP1)

Considertestingat-riskrelativesforthefamilialmutation(s)


Genemutation(s)detectedbyNGS.Mutation(s)reconfirmedbycapillarysequencing.Interpretivereportisprovided

No genemutation(s)detectedincustomizedgenesbyNGS.WholeexomeanalysisbyNGS


Genemutation(s)detectedbyNGS.Mutation(s)reconfirmedbycapillarysequencing.Interpretivereportisprovided

23 Probands on LDL-Apheresis and 2 probands had liver transplant at age 6 and 4.

**Homozygous patients*Heterozygous patients

Summary of FH samples received so far….

KFSHRC, Riyadh 17 22** 21 43 43

PSCC Riyadh 43 48** 122 170 170

NGH, Jeddah 18 18* - 18 18

KFSH, Jeddah 5 5* - 5 5

KFCC + KKH

Riyadh87 87* - 87 78

PSCC, Riyadh 8 8* - 8 -

SBCC,

Dammam18 18* - 18 18

KAUH, Jeddah 20 20* - 20 20

NGH, Riyadh 64 64* - 64 -

Total 280 290 143 433 352

# of samples

AnalyzedCenters

# of FH-

Families

# of

Probands# of relatives Total samples

No

. of

vari

ants

28

23

7

5

8

43

2

2019

43

0

5

10

15

20

25

30

LDLR APOB PCSK9 LDLRAP1

Total variants identified in FH associated genes

Total variants

Novel

Reported

GeneCoding

changeAmino acid change

Mutation

type

No. of

Patients

Frequency

(%)Geographical distribution

c.2027delG p.(G676Afs*33) Frameshift 69 20 Western, Central, Northern

c.1731G>T p.(Trp577Cys) Missense 21 6 Central, Eastern, Northern

c.2416dupG p.(Val806Glyfs*11) Frameshift 9 3 Central

c.9835A>G p.(Ser3279Gly) Missense 43 12 Western, Central, Eastern

c.8216C>T p.(Pro2739Leu) Missense 74 21 Western, Central, Eastern

c.1853C>T p.(Ala618Val) Missense 79 22 Western, Central, Eastern

c.5768A>G p.(His1923Arg) Missense 18 5 Western, Central

LDLR

APOB

Common variants detected in Saudi FH patients

*LDLR variant c.2027delG, p.(G676Afs*33) is more common in homozygous patients.Homozygous patients: 30%In total homozygous and heterozygous patients= 20%

c.9835A>G, p.(Ser3279Gly)c.8216C>T, p.(Pro2739Leu)c.1853C>T, p.(Ala618Val)

These three APOB variants are common in heterozygous patients and may be considered as a risk variants.

c.8216C>T, p.(Pro2739Leu)c.1853C>T, p.(Ala618Val)

These two variants are present as a APOB compound heterozygous in many patients.

Geographical distribution

LDLR:c.2027delG

LDLR:c.1731G>T

LDLR:c.2416dupG

Geographical distribution of LDLR common variants

88%

12%

83%

17%

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

Mutation positive Mutation Negative

Mutations detection rate in four FH associated gene (LDLR, APOB, PCSK9, LDLRAP1) in Saudi FH patients

Homozygous Probands

Heterozygous Probands

28

We need to collaborate with more centers, physicians, and researchers across the Gulf

We need to include other Arab patients from MENA

We need to activate the educational home page and FH registry

Future work

Dr Mohammad Athar, UQU, Makkah

Dr Taher Mohiddin, UQU, Makkah

Dr Zainularefeen Abduljaleel, UQU, Makkah

Dr Abdulatif Bouezzi, UQU, Makkah

Dr Iman Abo Mansoor, UQU, Makkah

Dr Zohor Azhar, UQU, Makkah

Mrs Mawaddah Toonsi, UQU, Makkah

Ms Aroob Alhemaidi, UQU, Makkah

Ms Ghaidaa Diari, UQU, Makkah

Mr Faisal Bahammam, UQU, Makkah

Mr Rakan Own, UQU, Makkah

Mr Aiman Al-Shingiti, UQU, Makkah

Mr Moaiad Al-Seraihi, UQU, Makkah

Mr Rami Bamerdhah, UQU, Makkah

Dr Maisaa Amer, UQU, Makkah

Dr Ahmad Faisal, UQU, Makkah

Dr Mahmood Alsayed, UQU, Makkah

The work is supported by a Grant Number 08-BIO34-10, the Long-Term National Plan for Science, Technology and Innovation, KACST

Dr. Abdullah Al-Ashwal, CoI, KFSH&RC, Riaydh

Dr. Hala Abalkhail, CoI, KFSH&RC, Riaydh

Dr. Fahad Alnoori, Prince Sultan Cardiac Centre, Armed ForceHospital, Riyadh

Dr Zohair Awan, KAU, Jeddah

Mr Ahmad Al-Allaf, AlFaisal University, Riyadh

Khalid F. AlHabib, Khalid Al Rasadi, Dr Wael Almahmeed, Dr

Abdullah Shehab, Dr Faisal Al-Allaf, Dr Fahad Al Noori, Dr Hussam

Alfaleh, Dr Zuhair Awan, Dr Abdulhalim Kensara, Dr Khalid Al-

Waili, Dr Fahad Al-Zadjali, Dr Ibrahim Al-Zakwani, Dr Nasreen

AlSayed, Dr Haitham Amin, Dr Ahmed Al-Sarraf, Dr Mohammed

Al-Jarallah, Dr Nidal Asaad, Prof Peter Lansberg, Mr Hani Altaradi

Thanks

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