Clouston syndrome
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Reviewed March 2014
What is Clouston syndrome?
Clouston syndrome is a form of ectodermal dysplasia, a group of about
150 conditions characterized by abnormal development of some or all of
the ectodermal structures, which include the skin, hair, nails, teeth,
and sweat glands. Specifically, Clouston syndrome is characterized by
abnormalities of the hair, nails, and skin, with the teeth and sweat
glands being unaffected.
In infants with Clouston syndrome, scalp hair is sparse, patchy, and
lighter in color than the hair of other family members; it is also
fragile and easily broken. By puberty, the hair problems may worsen
until all the hair on the scalp is lost (total alopecia). The eyelashes,
eyebrows, underarm (axillary) hair, and pubic hair are also sparse or
absent.
Abnormal growth of fingernails and toenails (nail dystrophy) is also
characteristic of Clouston syndrome. The nails may appear white in the
first years of life. They grow slowly and gradually become thick and
misshapen. In some people with Clouston syndrome, nail dystrophy is the
most noticeable feature of the disorder.
Many people with Clouston syndrome have thick skin on the palms of
the hands and soles of the feet (palmoplantar hyperkeratosis); areas of
the skin, especially over the joints, that are darker in color than the
surrounding skin (hyperpigmentation); and widened and rounded tips of
the fingers (clubbing).
150 conditions characterized by abnormal development of some or all of
the ectodermal structures, which include the skin, hair, nails, teeth,
and sweat glands. Specifically, Clouston syndrome is characterized by
abnormalities of the hair, nails, and skin, with the teeth and sweat
glands being unaffected.
In infants with Clouston syndrome, scalp hair is sparse, patchy, and
lighter in color than the hair of other family members; it is also
fragile and easily broken. By puberty, the hair problems may worsen
until all the hair on the scalp is lost (total alopecia). The eyelashes,
eyebrows, underarm (axillary) hair, and pubic hair are also sparse or
absent.
Abnormal growth of fingernails and toenails (nail dystrophy) is also
characteristic of Clouston syndrome. The nails may appear white in the
first years of life. They grow slowly and gradually become thick and
misshapen. In some people with Clouston syndrome, nail dystrophy is the
most noticeable feature of the disorder.
Many people with Clouston syndrome have thick skin on the palms of
the hands and soles of the feet (palmoplantar hyperkeratosis); areas of
the skin, especially over the joints, that are darker in color than the
surrounding skin (hyperpigmentation); and widened and rounded tips of
the fingers (clubbing).
How common is Clouston syndrome?
The prevalence of Clouston syndrome is unknown. Cases have been
reported in many populations; the disorder is especially common among
people of French-Canadian descent.
reported in many populations; the disorder is especially common among
people of French-Canadian descent.
What genes are related to Clouston syndrome?
Clouston syndrome is caused by mutations in the GJB6
gene. This gene provides instructions for making a protein called gap
junction beta 6, more commonly known as connexin 30. Connexin 30 is a
member of the connexin protein family. Connexin proteins form channels
called gap junctions, which permit the transport of nutrients, charged
atoms (ions), and signaling molecules between neighboring cells. The
size of the gap junction and the types of particles that move through it
are determined by the particular connexin proteins that make up the
channel. Gap junctions made with connexin 30 transport potassium ions
and certain small molecules.
Connexin 30 is found in several different tissues throughout the
body, including the skin (especially on the palms of the hands and soles
of the feet), hair follicles, and nail beds, and plays a role in the
growth and development of these tissues.
GJB6 gene mutations that cause Clouston
syndrome change single protein building blocks (amino acids) in the
connexin 30 protein. Although the effects of these mutations are not
fully understood, they lead to abnormalities in the growth, division,
and maturation of cells in the hair follicles, nails, and skin.
Read more about the GJB6 gene.
gene. This gene provides instructions for making a protein called gap
junction beta 6, more commonly known as connexin 30. Connexin 30 is a
member of the connexin protein family. Connexin proteins form channels
called gap junctions, which permit the transport of nutrients, charged
atoms (ions), and signaling molecules between neighboring cells. The
size of the gap junction and the types of particles that move through it
are determined by the particular connexin proteins that make up the
channel. Gap junctions made with connexin 30 transport potassium ions
and certain small molecules.
Connexin 30 is found in several different tissues throughout the
body, including the skin (especially on the palms of the hands and soles
of the feet), hair follicles, and nail beds, and plays a role in the
growth and development of these tissues.
GJB6 gene mutations that cause Clouston
syndrome change single protein building blocks (amino acids) in the
connexin 30 protein. Although the effects of these mutations are not
fully understood, they lead to abnormalities in the growth, division,
and maturation of cells in the hair follicles, nails, and skin.
Read more about the GJB6 gene.
How do people inherit Clouston syndrome?
This condition is inherited in an autosomal dominant pattern, which
means one copy of the altered gene in each cell is sufficient to cause
the disorder.
In most cases, an affected person inherits the mutation from one
affected parent. Other cases result from new mutations in the gene and
occur in people with no history of the disorder in their family.
means one copy of the altered gene in each cell is sufficient to cause
the disorder.
In most cases, an affected person inherits the mutation from one
affected parent. Other cases result from new mutations in the gene and
occur in people with no history of the disorder in their family.
Where can I find information about diagnosis or management of Clouston syndrome?
These resources address the diagnosis or management of Clouston syndrome and may include treatment providers.
Educational resources and Patient support.
General information about the diagnosis and management of genetic conditions is available in the Handbook.
Read more about genetic testing, particularly the difference between clinical tests and research tests.
To locate a healthcare provider, see How can I find a genetics professional in my area? in the Handbook.
- Gene Review: Hidrotic Ectodermal Dysplasia
2 - Genetic Testing Registry: Hidrotic ectodermal dysplasia
syndrome
Educational resources and Patient support.
General information about the diagnosis and management of genetic conditions is available in the Handbook.
Read more about genetic testing, particularly the difference between clinical tests and research tests.
To locate a healthcare provider, see How can I find a genetics professional in my area? in the Handbook.
Where can I find additional information about Clouston syndrome?
You may find the following resources about Clouston syndrome helpful. These materials are written for the general public.
MedlinePlus - Health information (2 links)
Educational resources - Information pages (5 links)
Patient support - For patients and families (2 links)
- Gene
Reviews - Clinical summary
Genetic Testing Registry - Repository of genetic test information (1 link)PubMed - Recent literatureOMIM - Genetic disorder catalog
What other names do people use for Clouston syndrome?
- Clouston hidrotic ectodermal dysplasia
- Clouston's syndrome
- ECTD2
- ectodermal dysplasia 2, Clouston type
- HED2
- hidrotic ectodermal dysplasia 2
For more information about naming genetic conditions, see the Genetics Home Reference
Condition Naming Guidelines
and
How are genetic conditions and genes named? in the Handbook.
What if I still have specific questions about Clouston syndrome?
Where can I find general information about genetic conditions?
The Handbook provides basic information about genetics in clear language.
What does it mean if a disorder seems to run in my family?
What are the different ways in which a genetic condition can be inherited?
If a genetic disorder runs in my family, what are the chances that my children will have the condition?
Why are some genetic conditions more common in particular ethnic groups?
What glossary definitions help with understanding Clouston syndrome?
acids ;
alopecia ;
autosomal ;
autosomal dominant ;
cell ;
channel ;
connexin ;
dysplasia ;
gap junctions ;
gene ;
ions ;
mutation ;
potassium ;
prevalence ;
protein ;
puberty ;
syndrome
You may find definitions for these and many other terms in the Genetics Home Reference
Glossary.
See also Understanding Medical Terminology.
References (10 links)
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.
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.
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