ultrasound:. machine using sound waves to look at physical features of the developing fetus...

Ultrasound:

Machine

Using sound waves to look at physical features of the developing fetus including size, anatomy, number of appendages/parts, sex, and heartbeat.

Amniocentesis

• Amniocentesis is a diagnostic prenatal test that allows doctors to collect information regarding the baby’s health by gathering amniotic fluid that has cells sloughed off from the growing fetus. The cells then can be analyzed for their DNA through gene testing and karyotyping.

Chronic villi sampling

Also tests cellular material. Causes spontaneous abortions sometimes, but can get more information.

A karyotype is chart of someone’s chromosomes. The chromosomes

are organized by size, large to small.

This arrangement helps scientists be able to identify genetic disorders caused by

chromosome alterations.

To be able to make a karyotype scientists take a picture of your chromosomes , cut them out and match them depending on size,

banding pattern and centromere position.

This is an examples of a karyotype. In this example it is

easy to see that this person has Klinefelter

syndrome due to the extra Y sex

chromosome.

Different dyes and computers make karyotyping easier today.

Gene Testing

• Since the Human Genome Project identified where genes are located and what they do, we now have developed many tests to examine what form of the gene a person has. This testing can be done on embryonic stem cells early in the development or for invitro fertilization OR it can be done on cells in amniotic fluid.

• Specific to one gene/protein, but many tests can be run on one sample at the same time. DNA chips are being developed.

• Mutation in the gene coding for a transmembrane protein in the lungs.

• Due to loss of chromosome, located on chromosome 7.

• Recessive

CYSTIC FIBROSIS: Recessive

What happens• Symptoms occur throughout the whole body• Newborns: Delayed growth• Bowels: Severe constipation • Lungs: Mucus build up

More on Cystic Fibrosis

• Blood tests look for variations of the gene in CFTR.• Exercising • Medicines (antibiotics, anti-inflammatory, bronchodilators)• Lung transplants for critical conditions

Cystic Fibrosis is common in the Caucasian population in the US. 1 in 2,500-3,500 Caucasian newborns 1 in 17,000 African Americans1 in 31,000 Asian Americans

Other recessive disorders

• Tay Sachs: can’t break down fats accumulating in the brain due to faulty enzyme (baby dies early), common in certain Jewish communities

• PKU: can’t break down phenylalanine amino acid, so low protein diet is needed.

• Sickle cell anemia: common in groups with ancestory in low latitude (tropics) as heterozygous condition protects from Malaria. African Americans most likely group in USA.

Down Syndrome: trisomy 21

• Chromosome 21

• Nondisjunction

• Trisomy 21

More on Down Syndrome

• Physical

• Mental

Hemophilia: sex-linked recessive

Recessive

F8 genes- Hemophilia A

F9 genes- Hemophilia B

Lack of protein- Factor VIII, IX

Hemophilia

Easy Bruising

Extended Bleeding

Tight joints

Swelling

BRCA 1 and 2: predisposition to Breast Cancer

• 5%-10% cases hereditary

• Caused by mutations on chromosomes 13/17 ( genes BRCA1 and BRCA2)

• What are my choices

Frequent mammograms and breast exams Surgery to remove a tumor or the whole breastChemotherapyHormone therapy

Klinefelter's Syndrome (trisomy XXY)& Turner’s Syndrome (monosomy XO)

Klinefelters: male with female secondary sex characteristics sometimes: others have very little symptoms

Turner’s syndrome: very serious female disorder with webbing, short stature, lack of development.

Huntingdon’s disease: dominant disorder

First shows after 35 years old.

SYMPTOMS35-44 years oldCognitive and PsychiatricAtrophy NeuronsDepression and AnxietyChorea