|http://ghr.nlm.nih.gov/ A service of the U.S. National Library of Medicine®|
The official name of this gene is “NAD(P) dependent steroid dehydrogenase-like.”
NSDHL is the gene's official symbol. The NSDHL gene is also known by other names, listed below.
The NSDHL gene provides instructions for making an enzyme that is involved in the production (synthesis) of cholesterol. Cholesterol is a lipid (fat) that is obtained from foods that come from animals, particularly egg yolks, meat, fish, and dairy products. The body can also make (synthesize) its own cholesterol. During cholesterol synthesis, the NSDHL enzyme participates in one of several steps that convert a molecule called lanosterol to cholesterol. Specifically, the NSDHL enzyme removes a carbon atom and three hydrogen atoms (a methyl group) in the conversion of lanosterol to cholesterol.
Although high cholesterol levels are a well-known risk factor for heart disease, the body needs some cholesterol to develop and function normally. Before birth, cholesterol interacts with signaling proteins that control early development of the brain, limbs, genital tract, and other structures. It is also an important component of cell membranes and myelin, the fatty covering that insulates nerve cells. Additionally, cholesterol is used to make certain hormones and is important for the production of acids used in digestion (bile acids).
The NSDHL gene belongs to a family of genes called SDR (short chain dehydrogenase/reductase superfamily).
A gene family is a group of genes that share important characteristics. Classifying individual genes into families helps researchers describe how genes are related to each other. For more information, see What are gene families? (http://ghr.nlm.nih.gov/handbook/howgeneswork/genefamilies) in the Handbook.
At least 18 mutations in the NSDHL gene have been found to cause congenital hemidysplasia with ichthyosiform erythroderma and limb defects (CHILD syndrome). Most of these mutations change single protein building blocks (amino acids) in the NSDHL enzyme. A few other mutations delete part or all of the NSDHL gene. Each of the identified mutations likely prevents the production of any functional NSDHL enzyme, which disrupts the normal synthesis of cholesterol within cells. A shortage of this enzyme may also allow potentially toxic byproducts of cholesterol synthesis to build up in the body's tissues. Researchers suspect that low cholesterol levels and/or an accumulation of other substances disrupts the growth and development of many parts of the body. It is not known, however, how a disturbance in cholesterol synthesis leads to the specific features of CHILD syndrome.
Cytogenetic Location: Xq28
Molecular Location on the X chromosome: base pairs 151,999,510 to 152,037,906
The NSDHL gene is located on the long (q) arm of the X chromosome at position 28.
More precisely, the NSDHL gene is located from base pair 151,999,510 to base pair 152,037,906 on the X chromosome.
See How do geneticists indicate the location of a gene? (http://ghr.nlm.nih.gov/handbook/howgeneswork/genelocation) in the Handbook.
You and your healthcare professional may find the following resources about NSDHL helpful.
You may also be interested in these resources, which are designed for genetics professionals and researchers.
See How are genetic conditions and genes named? (http://ghr.nlm.nih.gov/handbook/mutationsanddisorders/naming) in the Handbook.
acids ; atom ; bile ; carboxylate ; cell ; cholesterol ; congenital ; dehydrogenase ; digestion ; egg ; enzyme ; erythroderma ; gene ; ichthyosiform ; lipid ; methyl ; molecule ; protein ; syndrome ; synthesis ; toxic
You may find definitions for these and many other terms in the Genetics Home Reference Glossary (http://www.ghr.nlm.nih.gov/glossary).
The resources on this site should not be used as a substitute for professional medical care or advice. Users seeking information about a personal genetic disease, syndrome, or condition should consult with a qualified healthcare professional. See How can I find a genetics professional in my area? (http://ghr.nlm.nih.gov/handbook/consult/findingprofessional) in the Handbook.