Macular cherry-red spot is detected on eye exam. Prenatal manifestations may include nonimmune hydrops fetalis, intrauterine growth restriction, and placental vacuolization congenital dermal melanocytosis (Mongolian spots) may be observed. Type I (infantile) GM1 gangliosidosis begins before age 12 months. The phenotype of GM1 gangliosidosis constitutes a spectrum ranging from severe (infantile) to intermediate (late-infantile and juvenile) to mild (chronic/adult). GLB1-related disorders comprise two phenotypically distinct lysosomal storage disorders: GM1 gangliosidosis and mucopolysaccharidosis type IVB (MPS IVB). Children with MPS IVA have normal intellectual abilities at the outset of the disease. Compression of the spinal cord is a common complication that results in neurologic impairment. Involvement of other organ systems can lead to significant morbidity, including respiratory compromise, obstructive sleep apnea, valvular heart disease, hearing impairment, visual impairment from corneal clouding, dental abnormalities, and hepatomegaly. Progressive bone and joint involvement leads to short stature, and eventually to disabling pain and arthritis. The severe form is usually apparent between ages one and three years, often first manifesting as kyphoscoliosis, genu valgum (knock-knee), and pectus carinatum the slowly progressive form may not become evident until late childhood or adolescence, often first manifesting as hip problems (pain, stiffness, and Legg Perthes disease). Children with MPS IVA typically have no distinctive clinical findings at birth. The phenotypic spectrum of mucopolysaccharidosis IVA (MPS IVA) is a continuum that ranges from a severe and rapidly progressive early-onset form to a slowly progressive later-onset form. Database of Single Nucleotide Polymorphisms (dbSNP).Database of Genomic Structural Variation (dbVar).Online Mendelian Inheritance in Man (OMIM).
Conserved Domain Search Service (CD Search).BLAST (Basic Local Alignment Search Tool).