Niemann-Pick disease (NPD), is an inherited disease caused by the defective metabolism of sphingomyelin due to a malfunctioning enzyme called acid sphingomyelinase. As a result, sphingomyelin builds up in the body, causing cell apoptosis and prohibiting the proper function of certain organs. Mutations in the SMPD1 gene can cause either the type A form or the type B form of NPD.
NIEMANN-PICK DISEASE TYPE A (NPD-A)
NPD-A causes intellectual disability, loss of motor skills, and enlargement of the liver and spleen, among other symptoms. The disease is often fatal by the age of two or three. Symptoms of NPD-A usually begin within the first few months of life. By the age of six months, infants with the disease have difficulty feeding, display an enlarged abdomen, and will begin to lose the motor skills they have developed. Seizures and spastic movement are common. Most will not learn to sit independently, crawl, or walk. They have poor muscle tone and develop cherry-red spots in their eyes. Many have a yellow tinge to the skin and whites of the eye (jaundice). Intellectual and motor skills will progressively and rapidly decline.
NIEMANN-PICK DISEASE TYPE B (NPD-B)
Unlike type A, which is fatal in early childhood, individuals with NPD-B have a less severe course of the disease and may live into adulthood. The most common symptoms include an enlargement of the liver and spleen, a progressive decline in lung function and repeated respiratory infections and poor overall physical growth. They typically have abnormal lipid levels in their blood, with low HDL cholesterol and high LDL and triglycerides and may also have a decreased number of blood platelets. Individuals with NPD-B usually do not have the nervous system complications (i.e., loss of motor skills) found in NPD-A, but some individuals with the disease develop symptoms that combine features of both NPD-A and NPD-B.
Niemann-Pick disease is inherited in an autosomal recessive manner. It is caused by mutations in SMPD1 gene, that encodes for the lysosomal enzyme acid sphingomyelinase.
Genesis Genoma Lab offer the complete analysis of SMPD1 gene in order to detect possible mutations connected to the development of Niemann-Pick disease type Α or Β.
Sample type: Peripheral blood in EDTA
Time to result: 4 weeks