Fragile X syndrome

Question 1

What is it?

Answer 1

trinucleotide repeat disorder.

Question 2

features in males

Answer 2

learning difficulties
large low set ears, long thin face, high arched palate
macroorchidism
hypotonia
autism is more common
mitral valve prolapse

Question 3

features in females

Answer 3

(who have one fragile chromosome and one normal X chromosome) range from normal to mild

Question 4

diagnosis

Answer 4

can be made antenatally by chorionic villus sampling or amniocentesis

analysis of the number of CGG repeats using restriction

endonuclease digestion and Southern blot analysis