The goal of such testing is to prevent the conception or birth of at-risk babies, with termination being a commonly chosen solution.
For Tay-Sachs carriers who wish to bear a normal child, in vitro fertilization followed by testing of individual blastomeres and implantation of non-affected embryos is a reliable though expensive option.
This cherry-red spot is a characteristic that would eventually come to be associated with metabolic neurological disorders like Sandhoff, GM-1, Niemann-Pick, and, in recognition of Tay, the lysosomal storage disorder known as Tay-Sachs Disease.
Tay shares the disease’s title with New York neurologist Bernard Sachs, who described the cellular changes present in the disease as well as its potential for heritability, shortly after Tay’s observation.
Individuals with the juvenile form tend to develop symptoms similar to the classic infantile form between ages two and ten with death almost always occurring by age fifteen.
In contrast, individuals with LOTS experience symptoms that are less severe than both the class infantile and juvenile forms.The inability to suppress ganglioside levels results in toxic accumulation of GM2 in the nerve cells of the brain and spinal cord, ultimately leading to their destruction and to the symptoms associated with the disease.This is why Tay-Sachs Disease is also known as GM2 gangliosidosis type 1.Life expectancy is also variable and sometimes even unaffected.These symptoms result from the accumulation of a fatty substance in the brain due to the absence or suppression of an important enzyme known as hexosaminidase A, or Hex-A, that is a result of a mutation on both copies of the hexosaminidase A (alpha polypeptide), or HEXA, gene.A carrier for Tay-Sachs disease possesses one copy of the mutated HEXA gene but is phenotypically normal.If both parents are carriers, they have a one in four chance of producing a child who is homozygous for the trait, receiving both of the mutated HEXA genes, with any given pregnancy.As its name implies, the HEXA gene is essential to the production of the Hex-A enzyme, which is further comprised of alpha and beta subunits.Located on the long arm of chromosome 15, the HEXA gene contains genetic information that encodes for a particular protein involved in the formation of the enzyme’s alpha subunit. O’Brien discovered that Tay-Sach’s disease was in fact linked to diminished Hex-A activity and that this event was connected to a disturbed alpha subunit, which could be identified with an enzyme assay.A single-gene disease, Tay-Sachs results in an individual who has not met certain developmental milestones, depending on the expression of the gene the disease affects.In the Classic Infantile form, the destructive process begins in the fetus early in pregnancy, though children with Tay-Sachs appear normal at birth.