Genetics Flashcards
What is uniparental disomy?
person gets 2 copies of gene from same parent
Name syndrome inherited in uniparental disomy?
Chromosome 15
> Angelman
- Angel-MAMA
- loss of maternal copy where dad’s gene usually imprinted (silenced)
= no expression of critical gene
> Prader-Willi
- PAPA-Willi
- critical paternal part missing and maternal part normally imprinted (silenced)
Why do we do DNA testing in kids with CF?
Give parents an idea about prognosis.
Benefit of CF genetic testing:
- dx
- carrier testing
- prenatal genetic dx
- prognostic
Unilateral cleft palate kid. Advice regarding next pregnancy. You advise recurrence risk of?
4%
T or F: biologic parents are thin then child unlikely to be obese.
True.
- Birth wt not predictive; biologic parents predict obesity in child
What is the inheritance pattern for TS?
Autosomal dominant.
2/3 mutation= de novo.
Next child: 50% regardless of gender.
Inheritance pattern of ectopic thyroid:
Sporadic
- Thyroid genesis (including ectopic) usually sporadic.
Dad has hemophilia. Inheritance for future kids?
- 0% of sons
- 50% of daughters carrier
Bckgrd: 1 in 5K males. X linked. Some female carriers with mild bleeding dx (symp)
Child with Tuberous Sclerosis. Mother pregnant and wants to know if next child will have the same?
Recurrence Minimal
- Tub Sclerosis= AD BUT spontaneous mutation in most cases
- if parents (-) for mutation, recurrence risk 2%
Which of the following is AD:
- Tuberous Sclerosis
- Fragile X
- CF
- Hereditary Spherocytosis
- Cong. Adrenal Hyperplasia
- PKU
- Beta thalassemia
- Marfan Syndrome
x Tuberous Sclerosis
x Marfan Syndrome
x Hereditary Spherocytosis (2/3 AD and 1/3 AR)
Fragile X= X linked CF= AR CAH= AR PKU= AR Beta-Thal= AR
T or F: Marfan Syndrome is AR inherited.
False.
AD.
List 5 features of marfan syndrome:
- Ectopia Lentis (lens superior subluxation)
- Pneumo
- Aortic root dilation
- Mitral valve prolapse
- Hypermobility
- Pectus carinatum and pectus excavatum
- Scoliosis
- Arm to Ht > 1.05
- Long fingers
- Wrist and thumb signs
- Pes Planus (Flat feet)
T or F: 1/2 of all hearing loss is genetic.
True.
BUT most non-syndromic
Syndrome: Waardenburg, CHARE, alport, jervell and lange-nielsen (qtc), NF2
T or F: CMV is the most common cause of acquired congenital hearing loss.
True.
List 5 RF for hearing loss:
- TORCH (CMV)
- Low BW
- Apgar 0-4; 0-6 at 5 min.
- Ototoxic med (aminoglycoside, loop diuretic)
- bac meningitis
- Hyperbili
- vent > 5 d
- echo
- head injury
Baby w/ web neck, lymphedema of hand + feet, hypertrophic heart. Dx?
Noonan Syndrome
list 5 traits of noonan syndrome
1. webbed neck Cystic hygroma 2. lymphedema 3. pulmonic stenosis 4. hypertrophic cardiomyopathy 5. crytorchidism 6. short wide set eyes (hypertelorism) 7. Triangular shape with low set eyes 8. early motor delay + LD
How is Turner diff than Nooan:
Female only
L side heart (Coarc, HTN)
++ Renal anomalies (horseshoe kidney for example)
Primary hypogonad (amenorrhea, sterility)
DD less common (Noonan early motor delay + LD)
List 5 traits of William syndrome:
= Gene deletion syn
- Elfin facies (periorbital full, flat nasal bridge, full lips)
- Stellate iris (starburst pattern;= line on inside much lighter; blue green eyes)
- HTN
- Hyper-Ca (irritable, constipation, strong)
- GU (UTI, VUR)
- Connective tissue lax (joint ,scoliosis)
- Very verbal (cocktail party personality)
- Visual-spatial difficulty.
Name CNS finding w/ Sturge Weber Syndrome:
Leptomeningeal angioma.
What is Sturge Weber Syndrome?
- Port wine stain (facial capillary malformation; usually V1 V2)
- Leptomeningeal angioma (abN blood vessel in brain)
CC: stroke like episodes, hemiparesis on opposite side of stain - Glaucoma (abN blood vessel in eye)
T or F: Sturge Weber is inherited.
False.
NOT heritable.
Sporadic mutation in embryo.
T or F: you must do CNS imaging for Sturge Weber.
TRUE
R/O leptomeningeal angioma.
Rocker bottom feet. Cleft palate. AbN ears. Clenched hand with overlapping fingers.
Trisomy 18
Edwards