Genetics

Question 1

XXY

Answer 1

= klinefelters (can have mosaicism 47XXY/46XY, milder)
Primary hypogonadism in males - hypergonadotrophic (high LH and FSH), hypogonadism (low testosterone)
Diagnosed late with small testes and infertility
Incomplete puberty with low testosterone
Higher risk of metabolic/CVS/autoimmune diseases

Question 2

XO

Answer 2

= Turner’s
In females
Dysmorphic features at birth - webbed neck, low ears, short stature
Cardiac conditions eg aortic stenosis (young), mitral valve prolapse, coarctation of aorta

Question 3

Kallman syndrome

Answer 3

= hypogonadotrophic hypogonadism
Delayed or absent puberty, small penis and undescended testicles in boys
Often anosmia
Often kidney, cleft, dental, hearing and visual impairments also

Question 4

Fragile X

Answer 4

FMR1 gene
Associated ADHD, autism, seizures
More pronounced affect in males

Question 5

Trisomy 13

Answer 5

Patau syndrome
Reduced muscle tone, small head/eyes, cleft palate, polydactyly
Severe cardiac and neuro effects
High mortality in first few months

Question 6

Trisomy 18

Answer 6

Edward syndrome
Usually female
IUGR, >90% mortality in pregnancy and first year
Cardiac, renal, dysmorphic features, cleft, hearing

Question 7

G6PD deficiency

Answer 7

X linked recessive (so men get)
Mediterranean/African descent
Intravascular haemolysis, normocytic anaemia
Mostly asymptomatic, can get haemolytic anaemia following infection/broad beans/certain drugs
Or presents with prolonged neonatal jaundice
Heinz bodies on blood film

Question 8

Hereditary spherocytosis

Answer 8

Autosomal dominant
Northern European
Extravascular haemolysis, often presents with severe anaemia following parvovirus
Spherocytes on blood film
Commonly get splenomegaly, anaemia, increased reticulocytes, sometimes jaundice
Splenectomy if severe (but usually supportive tx)