A 12-year-old boy with mild intellectual disability is brought to the office by his adoptive parents for a routine physical examination. The parents say that the boy is adjusting well to a new school that has increased resources for children with learning disabilities. The patient was adopted as an infant and the birth family's history is unknown. His immunizations are up to date, and he has no allergies. Review of the patient's medical records is notable for cytogenetic studies that showed a small gap near the tip of the long arm of the X chromosome. Which of the following findings are likely to be present on this patient's physical examination?

Question

A 12-year-old boy with mild intellectual disability is brought to the office by his adoptive parents for a routine physical examination.  The parents say that the boy is adjusting well to a new school that has increased resources for children with learning disabilities.  The patient was adopted as an infant and the birth family's history is unknown.  His immunizations are up to date, and he has no allergies.  Review of the patient's medical records is notable for cytogenetic studies that showed a small gap near the tip of the long arm of the X chromosome.  Which of the following findings are likely to be present on this patient's physical examination?

Quizplus · Accepted Answer

Eductional Objective: Fragile X syndrome, an X-linked disorder, is the most common cause of inherited intellectual disability.  The pathogenesis involves an unstable expansion of trinucleotide repeats (CGG) in the fragile X mental retardation 1 (FMR1) gene.  Key physical findings include dysmorphic facial features (eg, large jaw, protruding ears, long face) and macroorchidism.

A 12-Year-Old Boy with Mild Intellectual Disability Is Brought to the Office