A 5-year-old male presents with mental retardation and is diagnosed with fragile X syndrome.When the parents ask what caused this,how should the geneticist respond? This was most probably caused from:

Question

Quizplus · Accepted Answer

Unaffected transmitting males have been shown to have more than about 50 repeated DNA sequences near the beginning of the fragile X gene.
Translocation effects do not result in mental retardation.
Inversions have no physical effects.
Fragile X is not related to nondisjunction.

A 5-Year-Old Male Presents with Mental Retardation and Is Diagnosed