Zaragoza

Question 1

Questions to ask before genetic testing?

Answer 1

1. Why? Indications to test
2. Who? Patient vs. family member
3. What? Biological sample
4. When? Age and patient health
5. How? Method/limitations
6. Where? Specific laboratory

Question 2

Three types of genetic test?

Answer 2

Cytogenic, Molecular, Metabolic

Question 3

Cytogenic tests measure?

Answer 3

Chromosomes

Question 4

Molecular tests measure?

Answer 4

DNA or RNA

Question 5

Metabolic tests measure?

Answer 5

Metabolite or Protein/Enzyme

Question 6

What happens in Meiosis I?

Answer 6

Homologous chromosomes separate

Question 7

What happens in Meiosis II?

Answer 7

Sister chromatids separate

Question 8

Karyotyping is sampled from?

Answer 8

Blood
Bone Marrow
Amniotic fluid
Placental tissue

Question 9

Indications for Cytogenic testing vs array CGH?

Answer 9

Patient with

• Phenotype suggestive of a chromosome abnormality
• Learning disabilities, speech delay, behavioral problems
• Developmental delay / mental retardation / Autism
• One or more congenital abnormalities
• Short stature
• Ambiguous genitalia
• Infertility
• Recurrent pregnancy losses

Family history of

• A chromosome rearrangement
• Mental retardation

Question 10

3 major diseases to test for in FISH vs Array-CGH?

Answer 10

Williams - 7q11.23 for elastin gene
Prader-Willi/Angelman -15q11-q13 PW/AS region
DiGeorge/VCF 22q11.2 for DiGeorge/VCF region

Question 11

Williams FISH?

Answer 11

Williams - 7q11.23 for elastin gene

Question 12

PW/AM FISH?

Answer 12

Prader-Willi/Angelman -15q11-q13 PW/AS region

Question 13

DiGeorge/VCF FISH?

Answer 13

DiGeorge/VCF 22q11.2 for DiGeorge/VCF region

Question 14

Array CGH detects?

Answer 14

Chromosome Imbalances

Question 15

Array CGH indication vs karyotype?

Answer 15

First line testing:

• Karyotype: suspect a disorder with a whole extra or missing chromosome
• FISH (single-probe): suspect a specific microdeletion or microduplication syndrome
• Microarray: multiple congenital anomalies and/or with unexplained intellectual disabilities

Question 16

A polymorphism is?

Answer 16

A variant present in greater than 1% of population

Question 17

Four types of DNA mutation?

Answer 17

• Silent: same AA
• Missense: changed AA
• Nonsense: early stop codon
• Frame shift- indels, changed reading frame

Question 18

Indications for DNA testing?

Answer 18

Diagnostic Confirm a suspected diagnosis Predictive Predict the possibility of future illness Carrier Detect carrier state (unaffected individual) Prenatal Determine status of fetus

Question 19

Indications for metabolic testing (lots of them)?

Answer 19

Failure to thrive
Mental retardation/Devel Delay
Recurrent unexplained illness
Seizures
Ataxia
Loss of psychomotor skills
Hypotonia
‘‘Coarse’’ appearance
Eye abnormalities
Recurrent somnolence/coma
Abnormal sexual differentiation Hepatosplenomegaly Metabolic/lactic acidosis Hyperuricemia Hyperammonemia Low cholesterol Structural hair abnormalities Unexplained deafness Bone abnormalities Skin abnormalities

Question 20

Test for klinefelter?

Answer 20

Karyotype

Question 21

Test for Williams?

Answer 21

FISH for 7q11.23

Question 22

Test for Fragile X syndrome?

Answer 22

CGG repeat in FMR1 gene

DNA test for repeats

Question 23

Test for familial hypertrophic cardiomyopathy?

Answer 23

DNA test for TNNT2 gene

Question 24

Test for San Felipo Syndrome?

Answer 24

Enzyme Test for NAGLU protein