Question

Metachromatic leukodystrophy is inherited by an _____ pattern of inheritance and results in a deficiency in _____:

A. Autosomal recessive; hexosaminidase A
B. Autosomal dominant; hexosaminidase A
C. Autosomal dominant; arylsulfatase A
D. Autosomal recessive; arylsulfatase A
E. Autosomal recessive; galactocerebroside β-galactosidase

Answer 1

Metachromatic leukodystrophy is inherited in an autosomal recessive pattern, and it results in a deficiency in arylsulfatase A.

Step-by-step explanation:

Metachromatic leukodystrophy (MLD) is inherited in an autosomal recessive pattern, which corresponds to a gene on one of the 22 autosomal chromosomes. People with this disorder have a deficiency in arylsulfatase A. With autosomal recessive inheritance, a person must inherit two copies of the abnormal gene, one from each parent, to express the disease. Carriers of one abnormal gene typically do not show symptoms but can pass the gene to their offspring. For a child to be affected by MLD, both parents must be carriers of the defective gene. Therefore, the correct answer to the student's question is D. Autosomal recessive; arylsulfatase A.