Reviewed July 2008
What is the official name of the NSDHL gene?
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.
What is the normal function of the NSDHL gene?
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).
How are changes in the NSDHL gene related to health conditions?
-
congenital hemidysplasia with ichthyosiform erythroderma and limb defects - caused by mutations in the NSDHL gene
-
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.
Where is the NSDHL gene located?
Cytogenetic Location: Xq28
Molecular Location on the X chromosome: base pairs 151,750,166 to 151,788,562
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 151,750,166 to base pair 151,788,562 on the X chromosome.
See How do geneticists indicate the location of a gene? in the Handbook.
Where can I find additional information about NSDHL?
You and your healthcare professional may find the following resources about NSDHL helpful.
- Educational resources - Information pages
- Gene Tests - DNA tests ordered by healthcare professionals
You may also be interested in these resources, which are designed for genetics professionals and researchers.
- PubMed - Recent literature
- OMIM - Genetic disorder catalog
-
What other names do people use for the NSDHL gene or gene products?
- H105E3
- NSDHL_HUMAN
- Sterol-4-alpha-carboxylate 3-dehydrogenase, decarboxylating
- XAP104
Where can I find general information about genes?
The Handbook provides basic information about genetics in clear language.
These links provide additional genetics resources that may be useful.
What glossary definitions help with understanding NSDHL?
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? in the Handbook.