A 5-year-old boy has global developmental delay, marked language delay and autistic features. Examination shows large ears and hyperextensible finger

Question

A 5-year-old boy has global developmental delay, marked language delay and autistic features. Examination shows large ears and hyperextensible finger joints. His maternal uncle has intellectual disability. What is the most appropriate investigation?

Accepted Answer

FMR1 repeat expansion testing

Answer

Karyotype alone as the definitive test

Answer

Urine metabolic screen as the first test

Answer

MRI brain before genetic testing

Answer

Serum creatine kinase

Fragile X syndrome — RACP Paediatrics MCQ

A 5-year-old boy has global developmental delay, marked language delay and autistic features. Examination shows large ears and hyperextensible finger joints. His maternal uncle has intellectual disability. What is the most appropriate investigation?