A 27-year-old pregnant woman of Ashkenazi Jewish descent presents with her partner, a man of Cajun descent, to the nurse practitioner for a prenatal visit. Which rare inherited disorder, which progressively destroys neurons in the brain and spinal cord, should the couple be screened for?

Choice A reason: Huntington’s disease is a neurodegenerative disorder caused by a trinucleotide repeat expansion in the HTT gene. It is inherited in an autosomal dominant pattern and typically presents in mid-adulthood. It is not commonly screened for in prenatal visits unless there is a known family history. Choice B reason: Cystic fibrosis is a common autosomal recessive disorder affecting the lungs and pancreas. While it is included in many prenatal screening panels, it does not primarily cause progressive destruction of neurons in the brain and spinal cord. It is more associated with respiratory and gastrointestinal complications. Choice C reason: Muscular dystrophy refers to a group of genetic disorders characterized by progressive muscle weakness. While some forms, like Duchenne muscular dystrophy, are screened for in certain populations, they do not primarily affect neurons in the brain and spinal cord. Choice D reason: Tay-Sachs disease is a rare autosomal recessive disorder caused by a deficiency of the enzyme hexosaminidase A. It leads to progressive neurodegeneration and is especially prevalent among individuals of Ashkenazi Jewish and Cajun descent. Prenatal screening is recommended for couples from these backgrounds due to the increased carrier frequency.