<unk>  is severely under-diagnosed. It is often misdiagnosed as cerebral palsy. In the Ashkenazi Jewish population there are two severe mutations with a higher carrier frequency of 1:90 to 1:100.
Mucolipidosis type IV
GM2-gangliosidosis, AB variant
GM1 gangliosidoses
Mucopolysaccharidosis type I
GM2 gangliosidoses
Glycogen storage disease type VI
Glycogen storage disease type V
Sphingolipidoses