Regarding Fragile-X syndrome,
A) the affected females have nonfunctional ovaries, and estrogen production occurs at negligible levels.
B) the cause is trisomy, a mistake that occurs in meiosis, and affected individuals carry an extra chromosome.
C) the phenotype is male, but the testes fail to mature so the individuals are sterile, and the breasts are slightly enlarged.
D) the cause is a kind of chromosomal deletion known as monosomy where the phenotype is normal female.
E) the affected individuals display mental retardation, abnormal facial development, and enlarged testes in affected males.

Question

Quizplus · Accepted Answer

Fragile-X syndrome is caused by a mutation in the FMR1 gene, located on the X chromosome. The affected individuals have a range of symptoms, including mental retardation, abnormal facial development, and enlarged testes in affected males. Females who carry the mutation may show milder symptoms or be asymptomatic, but they can still pass the mutation to their offspring.

Regarding Fragile-X Syndrome