A 14-year-old intellectually disabled child presented to the OPD for the first time with hyper-extensible finger joints and macro-orchidism along with characteristic facial features. MRI of the brain was done. Which of the following sequence repeats is seen in the above condition: -
This is a case of Fragile- X syndrome. MRI image shows diffuse brain atrophy. X-linked dominant inheritance. The facial features, which include a long face, large ears, and a prominent square jaw. There are variable number of trinucleotide (CGG) repeats in FMR1 gene.
CGG
CGA
CAG
CGC
Integrated QBank