Select the FALSE statement about Gaucher disease :

Homozygous or compound heterozygous mutations in the GBA$1(1$q$22)$gene give rise to various forms of Gaucher disease with injury to the bone marrow and spleen, and possibly the brain as well.

The suspected diagnosis is confirmed by assay of glucocerebrosidase in circulating leukocytes, followed by DNA sequencing of the GBA$1$gene if the enzyme activity is low.

A knowledge of the mutations in each GBA$1$allele is sufficient to predict the type and severity of Gaucher disease.

Enzyme replacement therapy $($ERT$)$uses IV infusions of recombinant glucocerebrosidase.$$Macrophages and other leukocytes can take up the plasma enzyme via endocytosis, trafficking the vesicles to their lysosomes, but this protein does not cross the blood$-$brain barrier to reach CNS neurons.

Substrate reduction therapy $($SRT$)$uses oral inhibitors of glucocerebroside synthesis.

A complete inhibition of glucocerebroside synthesis would itself injure neuronal and other tissues that require glucocerebroside, and various glycosphingolipids derived from it$,$for their normal functions.