12.0 Prenatal Diagnosis Flashcards Preview

MedST IB: Human Reproduction (HR) > 12.0 Prenatal Diagnosis > Flashcards

Flashcards in 12.0 Prenatal Diagnosis Deck (23)
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1

What is the inheritance pattern of the following:

1) Cystic fibrosis
2) Myotonic dystrophy
3) Duchenne muscular dystrophy
4) Congenital adrenal hyperplasia
5) Huntington disease

1) Cystic fibrosis - AR
2) Myotonic dystrophy - AD
3) Duchenne muscular dystrophy - XLR
4) Congenital adrenal hyperplasia - AR
5) Huntington disease - AD

2

What are the 2 main neural tube defects?

1) Anencephaly
2) Spina bifida

3

What is anencephaly caused by?

Failure of closure of anterior neuropore

4

What is spina bifida caused by?

Failure of closure of posterior neuropore

5

What are open neural tube defects?

The neural tissues and meninges are exposed
Occurs in 100% of anencephaly
Occurs in majority of spina bifida
Maternal serum has ↑ Alpha fetoprotein

6

What are closed neural tube defects?

Skin covers defect
15-20% of spina bifida
Not detectable biochemically (No ↑ in alpha fetoprotein)

7

What can reduce incidence of neural tube defects?

Folic acid

8

What is Trisomy 21?

Down's syndrome

9

What translocation can cause Down's syndrome?

14:21

10

What percentage of Trisomy 21 are primary trisomy and what percentage are due to translocation?

Primary trisomy = 95%
Translocation = 5%

11

Signs + symptoms of Down syndrome:

• Intellectual disability (mild-moderate learning difficulties)
• Dysmorphic
o Flat nasal bridge
o Up slanting palpebral fissures
o Epicanthic folds
o Protruding tongue
o Single palmer crease
o Clinodactyly
o Sandal gap
• Cardiac defects
o 40% of cases

12

What is Trisomy 18?

Edward syndrome

13

Signs + symptoms of Edward syndrome:

• Intellectual disability (severe)
• Dysmorphic
o Micrognathia
o Prominent occiput
• Clenched + overlapping fingers
• Prominent heels and rocker-bottom feet
• Cardiac defects


Most die before 1yr

14

What is Trisomy 13?

Patau syndrome

15

Signs + symptoms of Patau syndrome:

• Mental disability (severe)
• Dysmorphic
o Cleft lip + palate
o Holoprocencephaly
o Postaxial polydactyly
• Renal abnormalities
• Cardiac defects

Most die before 1yr

16

What are sex chromosomes in Turner syndrome?

XO

17

What are sex chromosomes in Klinefelter syndrome?

XXY

18

What conditions cause increase nuchal translucency (NT) thickness measurements?

1) Trisomy 21
2) Cardiac defects
3) Venous congestion of head and neck
4) Abnormal lymph development
5) Neuromuscular disorders
6) Fetal anaemia
7) Congenital infection

19

What conditions cause a lemon or banana sign on ultrasound?

1) Spina bifida
2) Chiari II malformation

20

What conditions cause increase in maternal serum alphafetoprotein levels?

1) Neural tube defects (open)
2) Trisomy 21

21

What serum markers increase with trisomy 21?

1) Alphafetoprotein
2) Unconjugated estriol
3) hCG (largest increase)

22

Risk of miscarriage with chorionic villus sampling?

1-2%

23

Risk of miscarriage with amniocentesis?

0.5%