Select the FALSE statement about Tay$-$Sachs disease :

GM$2$ gangliosidoses are progressive neurodegenerative disorders caused by loss$-$of$-$function mutations in any of the genes HEXA $(15$q$23),$ HEXB $(5$q$13)$ or GM$2$A $(5$q$33).$

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Hexosaminidase A and its associated GM$2$ activator protein are found in most tissues, but their deficiency causes severe swelling and cell death only in neurons.

Individuals from high$-$risk populations $($carrier frequencies ca$.1/30),$ or with a family history of Tay$-$Sachs disease, can learn their carrier status from serum screening for hexosaminidase A$,$ followed by DNA sequencing if the serum activity is low.$$

Infants of parents who are both carriers of a null allele of HEXA have a prior risk $1/4$ of Tay$-$Sachs disease. Prenatal testing can be used to decide whether to continue $($normal & carrier$)$ or terminate $($affected$)$ the pregnancy. Where legal, elective abortion has reduced the incidence of Tay$-$Sachs disease in high$-$risk communities by as much as $90\%.$

Prenatal testing cannot reliably predict the occurrence, or the severity of Tay$-$Sachs disease.

During their first few months, Tay$-$Sachs infants develop normally.