A male child presented with coarse facies, protuberant abdomen , frontal head enlargement, thickening of cardiac valve, hepatosplenomegaly, hearing impairement. What is the most probable diagnosis?
Hurler's disease
Hunter's disease
Fragile X syndrome
Tay Sach's disease
Coarse facial features is a typical feature of Mucopolysaccharidosis (MPS). Hunter's disease is Type II Mucopolysaccharidosis, in which enzyme deficient is Iduronate Sulfatase. This is X-linked recessive, so occurs exclusively in Males. There is no corneal clouding in Hunter's disease. Option 3- Fragile X-Syndrome is a trinucleotide repeat expansion disorder in which patient has large face, large mandible, large testis, large eveed ears and tall stature. It is the second most common cause of mental retardation. Option 4- Tay Sach's disease is because of increased GM2 Gangliosides due to deficiency of enzyme Hexosaminidase A. Clinical features are mental retardation, cherry red spots on macula and progressive neurodegeneration but no hepatosplenomegaly. ADDITIONAL EDGE: Mucopolysaccharidosis: Type Disease name Enzyme defect Special features GAG accumulated MPS I - H (AR) Hurler disease Alpha - L - Iduronidase Inguinal hernias often present DS + HS MPS I - S (AR) Scheie disease Alpha - L - Iduronidase No mental retardation DS MPS II (XR) Hunter disease (Mild Hurler + Aggressive behaviour) Iduronate Sulfatase No corneal clouding, Exclusively males affected DS + HS MPS VI (AR) Maroteaux Lamy Syndrome Aryl Sulfatase B No mental retardation DS AR- Autosomal Recessive; XR- X-linked Recessive Additional Edge: C/F of Hunter disease Copious nasal discharge. Mental retardation. Coarse facies. Protuberant abdomen because of hepatomegaly and also inguinal hernia in these patients. frontal head enlargement. Thickening of cardiac valve. Hearing impairment. These patients have skeletal abnormalities because these mucopolysaccharides will be accumulated in bones also. And, all mucopolysaccharidosis have corneal clouding except hunter's disease.