P020ADevelopmental Disabilities

Mrs. Elizabeth Keele, RN

Course Objective #23• Identify the metabolic problem and the resulting presentation

in each of the following recessive inheritance syndromes:– Phenylketonuria– Galactosemia– Tay-Sachs Disease– Hurler Syndrome– Lesch-Nyhan Syndrome– Gaucher’s disease– Neimann-Pick Disease– Wilson’s Disease– Cretinism

Phenylketonuria

• AKA:– PKU

• Gene on chromosome 12– maybe 4 & 11

• Most common inborn error of metabolism

• Incidence– 1:10,000 in USA– carrier 1:50

Phenylketonuria

• Cannot breakdown phenylalanine – h phenylalanine – toxic to CNS

• Screening test – Guthrie test

• Screening timeline– After first 24 hrs. or

before 7-14 days

PhenylketonuriaCommon Features

• Appear – 7-10 days after birth

• ID– if not treated early

• Blond & fair• Musty odor• Microcephaly

PhenylketonuriaCommon Problems

• Vomiting• Irritability• Dry skin / Rash• Seizures

PhenylketonuriaCommon Problems

• “Maternal PKU”

PhenylketonuriaCommon Problems

• If noncompliant with diet – lower IQ– Learning disabilities– behavior problems– Tremors– Eczema– Impaired

communication

PhenylketonuriaCommon Treatment

• TREATABLE!!!!• Low-protein

/phenylalanine diet • Monitor blood

phenylalanine levels• Skin care • Symptom tx

PhenylketonuriaCommon Treatment

• Prevent maternal PKU by – adhering to diet – three months

before/during pregnancy

Galactosemia

• Chromosome 9• Missing liver enzyme– can’t digest milk-

products– Galactose

• Incidence – 1:20,000-1:60,000 live

births

Glactosemia - Pathophysiology

• If an infant with galactosemia is given milk, – Galactose – Toxic levels– Damage

• Liver• Brain• Kidneys• Eyes

GalactosemiaCommon Features

• S&S appear quickly– Vomiting– Jaundice– Lethargy– Irritability– Seizures

• ID is preventable• S&S may be due – E. coli.

GalactosemiaCommon Problems

• Severe ID–Aminoaciduria–Amino acids in

blood • Hepatomegaly– Enlarged liver

• Ascites• Hypoglycemia

If not treated…• Cataracts• Cirrhosis of the liver• Death • Delayed speech • i ovarian failure• Intellectual disability• E. coli sepsis• Tremors and

uncontrollable motor functions

GalactosemiaCommon Treatment

• Galactose-free diet– life-long

• Calcium supplements

Tay-Sach’s Disease

• Chromosome 15 • Incidence:– 1:30 Jews– 1:270 general population

Tay Sach’s

• Body lacks Hexosamindase A

• h Ganglioside • Nerve and brain cell

destruction • Deathmosis

Tay-Sach’s DiseaseCommon Features

• Appear – about 3-6 months

• Deaf & blind• i muscle tone• Irritable • Paralysis• Seizure

Tay-Sach’s DiseaseCommon Problems

• No cure or treatment• Death by 5 yrs

Tay-Sach’s DiseaseCommon Treatment

• Supportive care• Grief counseling

Hurler’s Syndrome

• AKA:– Gargoylism– Hunter’s

• Cannot breakdown sugar molecule– Glycosaminoglycans

Hurler’s SyndromeCommon Features

–h Muccopolysaccharides /Glycosaminoglycans–Symptoms appear • “Normal” birth• @ 2 yrs

Hurler’s SyndromeCommon Features

• Claw hand• i growth• Heart valve problems• Joint Disease• Thick, coarse facial

features • ID - progressive

Hurler’s SyndromeCommon Problems

• Dwarfism & kyphosis

• Deaf• Corneal clouding• Cardiac • ID

Hurler’s Syndrome-Common Treatment

• Supportive care• Prognosis–Poor

Lesch-Nyhan Syndrome

• AKA – Hyperuricemia– Lip-Biting Syndrome

• X-linked recessive• Incidence – 1:100,000 males

Lesch-Nyhan Syndrome

• Lack enzyme needed to recycle purines

• h uric acid • S&S appear – by 3-6 months

Lesch-Nyhan Syndrome- Common Features

• h uric acid level• Progressive ID• Compulsive, self-

destructive behavior

Lesch-Nyhan SyndromeCommon Problems

• Gout• Kidney stones• Self-mutilation– Lips, mouth, tongue,

fingers

Lesch-Nyhan Syndrome-Common Treatment

• Rx to reduce uric acid– Allopurinol

• Behavior modification• Hydration• Safe environment

Gaucher’s Disease

• Incidence – 1:1,000 Jews

• Chromosome 1• Various types

Gaucher’s Disease-Common Features

• Glucocerebroside (lipid) accumulates in visceral organs

• S&S appear– Different ages

Gaucher’s Disease-Common Features

• Progressive neurological deterioration

• Affects– Liver– Spleen– Lungs– Bone marrow– Brain

Gaucher’s Disease-Common Problems

• Progressive neurological problems

• ID• Bone/joint pain • Type I fatal

Gaucher’s Disease-Common Treatment

• Genetic counseling • Enzyme

replacement therapy

Niemann-Pick Disease

• Gene on chromosome 11

• Incidence – 1:450 Jews– 1:100,000 gen. Pop.

• Can’t metabolize sphingomyelin

Niemann-Pick Disease -Common Features

• h Sphingomyelin • Lipid storage

disease • Cell death &

organ failure

Niemann-Pick Disease -Common Problems

• ID • Progressive motor

skills loss• Enlarged

liver/spleen – jaundice

• S&S r/t –organs affected

Niemann-Pick Disease -Common Treatment

• Supportive & symptomatic• Genetic

counseling

Wilson’s Disease

• Gene on chromosome 13

• Can’t metabolize– copper

• S&S appear –5 -35 yrs

Wilson’s Disease-Common Features

• h Copper• Affects –Liver–CNS–Kayser-Fleischer

rings

Kayser-Fleischer Rings

Wilson’s Disease-Common Treatment

• i Copper diet • water supply

Congenital Hypothyroidism (Cretinism)

• AKA – Congenital

Hypothyroidism• absence/deficiency of– thyroid hormone

• Early diagnosis critical to prevent ID

• Dx tests: – T3, T4, TSH

Congenital Hypothyroidism (Cretinism)-Common Features

• Dwarfism• Large tongue, • Low metabolic rate• Intolerance to cold

Congenital Hypothyroidism (Cretinism)-Common Problems

• ID• Poor feeding, • Constipation• Short

Congenital Hypothyroidism (Cretinism)-Common Treatment

• Early dx• Replace – Thyroid hormone

Course Objective #24

• Describe features of the following multiple etiology congenital disorders:–Cornelia de Lange Syndrome–Laurence-moon syndrome

Cornelia de Lange Syndrome

• AKA – Brachmann-de Lange

• R/T chromosome 3

Cornelia de Lange Syndrome-Common Features

• Microcephaly• Hirsutism• Low birth weight – failure to thrive

• Short stature• ID – – Severe

• Clinodactyly,• Syndactyly• Cleft palate

Cornelia de Lange Syndrome-Common Problems

• ID• Self-mutilation• Behavior problems• Seizures• Cleft palate• Hearing loss & speech

delay

Cornelia de Lange Syndrome-Common Treatment

• GH• Communication

aides• Special education• Behavior

modification

Laurence-Moon Syndrome

• Genes on chromosomes– 11, 13, 15, 16

• Incidence – :13,500 Arabs in Kuwait– 1:160,000 gen. pop

Laurence-Moon SyndromeCommon Features

• Gen. obesity • Dwarfism• Skeletal defects• Progressive vision

problems• Hypogenitalism

Laurence-Moon Syndrome-Common Problems

• ID • Blindness• Kidney & cardiac

disorders• Speech problems• Syndactyly• Polydactyly

Laurence-Moon Syndrome-Common Treatment

• Diet• Visual aides• SLP • Kidney care • Surgery – to remove extra

digits

Course Objective #25

• Differentiate between microcephaly and macrocephaly

Microcephaly

• Causes

Microcephaly-Common Features

• Small head

Microcephaly-Common Problems

• ID• Strabismus• Hypertonia• Seizures• Behavior problems

Microcephaly-Common Treatment

• Early intervention• Anticonvulsant

medication

Shunt

Megaloencephaly• 1o – no underlying disease

• 2o – D/T metabolic D/O

• ID– May be normal, MR or

>IQ

Megaloencephaly-Common Features

• h brain weight– > 1600 g

• Normal– 1350-1400 g

• Deformed skull

Megaloencephaly-Common Problems

• ID / DD• Seizures• Neuro deficits

Megaloencephaly-Common Treatment

• Symptomatic treatment

Course Objectives #27

• Explain the difference between cultural-familial retardation and psychosocial disadvantage

Cultural-Familial Retardation

• ID– Mild

• No – Physical disability

• D/T– Environmental causes

• Poor prenatal care• Nutrition• Disease• Toxins

Psychosocial ID

• D/T– psychosocial factors– No organic cause

• Not reversible

• Abuse family• Neglect family

Course #28

• Explain what is meant by a neural tube defect and describe the difference between the various forms of this type of disorder.

Spinal BifidaPathophysiology• Congenital Neural Tube

defect• Incomplete closure of the

vertebrae• 3 Levels

– Spina Bifida Occulta– Meningocele– Myelomeningocele

Spina bifida occulta

• Bones of the spine do not close• But the spinal cord and meninges

remain in place• And skin usually covers the defect

Meningocele

• Meninges protrude from the spinal canal• But the spinal cord remains in place

Myelomeningocele

• Both the spinal cord and the meninges protrude from the spinal canal• Co-morbidity–Hydrocephalus

Spinal Bifida• Myelomeningocele must have a

repair of the open neural tube. Failure to repair may result in serious infection which would harm the developing infant brain. After the repair, many children require the insertion of a device called a shunt to divert the cerebral spinal fluid to treat the hydrocephalus.

The Infant with Myelomeningocele

Spinal BifidaEtiology• Idopathic• Folic acid deficiency

during pregnancy– Esp 1st month

Spinal Bifida

Diagnosis• Ultrasound• h Alpha fetoprotein

Spinal Bifida• What food contain folic

Acid?– Greens– Asparagus– Broccoli– Cauliflower– Corn– Green Beans or Peas– Sweet Potato– Cabbage or Coleslaw

– Black Beans– Lentils– Peas– Peanuts

Course Content #29

• Identify non-genetic biological causes of development disabilities factors that are required–Prenatally–Perinatally–Postnatally

Prenatal

• Toxic substances• Infection

Perinatal

• Premature • Birth injuries– Deprived of O2– Forceps – Nuchal chord

Postnatal

• Brain damage: – Infections• Encephalitis• Meningitis– vaccinations

• mosquitoes • Lead poisoning

– TBI

• Prenatal – Toxic substances (drugs, alcohol)– Infection

• Perinatal– Delivery complications

• Postnatal– Head Injury– Infection