Medical Laboratory Scientist (MLS) ASCP Practice Exam

Tay-Sachs Disease is accurately characterized by a near-total deficiency of the enzyme N-acetylbetahexosaminidase A. This enzyme is crucial for the breakdown of certain lipids, particularly GM2 gangliosides, in the lysosomes. The deficiency leads to an accumulation of GM2 gangliosides in the nerve cells, which ultimately results in the progressive neurodegenerative symptoms associated with Tay-Sachs.

Individuals with Tay-Sachs typically exhibit symptoms such as developmental delay, loss of motor skills, and other neurological signs within the first few months of life. The disorder is inherited in an autosomal recessive pattern, meaning that both parents must carry a copy of the mutated gene for their child to be affected.

In contrast, the other disorders mentioned involve different pathophysiologies. Sickle Cell Disease is primarily caused by a mutation in the hemoglobin gene, leading to misshapen red blood cells. Hemophilia is a bleeding disorder due to deficiencies in clotting factors, while Thalassemia is related to defects in hemoglobin production. None of these disorders involve the deficiency of N-acetylbetahexosaminidase A, which is specific to Tay-Sachs Disease.