Which physical finding is often seen in adolescents with Fragile X syndrome?

Which physical finding is often seen in adolescents with Fragile X syndrome?

• A. Macroorchidism
• B. Micrognathia
• C. Macroglossia
• D. Scoliosis

Answer: (A)

Macroorchidism, or enlarged testes, is a classic finding in males with Fragile X syndrome, especially after puberty. Fragile X is caused by a CGG repeat expansion in the FMR1 gene, leading to reduced FMRP and a range of features including intellectual disability and distinctive facial characteristics. As boys enter adolescence, the testes commonly enlarge more than expected, making macroorchidism a helpful clinical clue for the diagnosis. In contrast, the other options are not characteristic of Fragile X: small jaw is not typical, a large tongue occurs more with other syndromes like Down syndrome, and scoliosis can occur in many conditions but is not a hallmark of Fragile X.

Macroorchidism, or enlarged testes, is a classic finding in males with Fragile X syndrome, especially after puberty. Fragile X is caused by a CGG repeat expansion in the FMR1 gene, leading to reduced FMRP and a range of features including intellectual disability and distinctive facial characteristics. As boys enter adolescence, the testes commonly enlarge more than expected, making macroorchidism a helpful clinical clue for the diagnosis. In contrast, the other options are not characteristic of Fragile X: small jaw is not typical, a large tongue occurs more with other syndromes like Down syndrome, and scoliosis can occur in many conditions but is not a hallmark of Fragile X.