Naegeli–Franceschetti–Jadassohn syndrome (NFJS), also known as chromatophore nevus of Naegeli and Naegeli syndrome,
is a rare
autosomal
An autosome is any chromosome that is not a sex chromosome. The members of an autosome pair in a diploid cell have the same morphology, unlike those in allosomal (sex chromosome) pairs, which may have different structures. The DNA in autosome ...
dominant form of
ectodermal dysplasia
Ectodermal Dysplasia (ED) refers to a group of genetic disorders characterized by the abnormal development or function of two or more structures that originate from the ectoderm, the outer layer of an embryo. These structures include hair, teeth ...
, characterized by reticular skin pigmentation, diminished function of the sweat glands, the absence of teeth and
hyperkeratosis
Hyperkeratosis is thickening of the stratum corneum (the outermost layer of the epidermis, or skin), often associated with the presence of an abnormal quantity of keratin,Kumar, Vinay; Fausto, Nelso; Abbas, Abul (2004) ''Robbins & Cotran Pathol ...
of the palms and soles. One of the most striking features is the absence of
fingerprint
A fingerprint is an impression left by the friction ridges of a human finger. The recovery of partial fingerprints from a crime scene is an important method of forensic science. Moisture and grease on a finger result in fingerprints on surfa ...
lines on the fingers.
Naegeli syndrome is similar to
dermatopathia pigmentosa reticularis, both of which are caused by a specific defect in the keratin 14 protein.
Cause
NFJS is caused by mutations in the
keratin 14
Keratin 14 is a member of the type I keratin family of intermediate filament proteins. Keratin 14 was the first type I keratin sequence determined.
Keratin 14 is also known as cytokeratin-14 (CK-14) or keratin-14 (KRT14). In humans it is encoded ...
(KRT14) gene, located on
chromosome
A chromosome is a package of DNA containing part or all of the genetic material of an organism. In most chromosomes, the very long thin DNA fibers are coated with nucleosome-forming packaging proteins; in eukaryotic cells, the most import ...
17q12-21.
[ The disorder is inherited in an autosomal dominant manner, which means that the defective gene responsible for a disorder is located on an ]autosome
An autosome is any chromosome that is not a sex chromosome. The members of an autosome pair in a diploid cell have the same morphology, unlike those in allosomal (sex chromosome) pairs, which may have different structures. The DNA in autosomes ...
(chromosome 17 is an autosome), and only one copy of the defective gene is sufficient to cause the disorder, when inherited from a parent who has the disorder.
Diagnosis
In most cases of Naegeli syndrome, a diagnosis is made based on the typical clinical features of this condition. The diagnosis may be confirmed by genetic testing
Genetic testing, also known as DNA testing, is used to identify changes in DNA sequence or chromosome structure. Genetic testing can also include measuring the results of genetic changes, such as RNA analysis as an output of gene expression, or ...
of the ''KRT14'' gene.
Treatment
Treatment for Naegeli syndrome is based on an individual's symptoms. Dry skin can be moisturized with creams. Exposure to heat should be limited. To avoid overheating, affected individuals should stay hydrated, wear appropriate clothing, and use wet dressings. Dental care is needed to treat cavities and tooth loss.
Eponym
It was named after Oskar Nägeli, Adolphe Franceschetti, and Josef Jadassohn.
See also
* List of cutaneous conditions
Many skin conditions affect the human integumentary system—the organ system covering the entire surface of the Human body, body and composed of Human skin, skin, hair, Nail (anatomy), nails, and related muscle and glands. The major function o ...
* List of cutaneous conditions caused by mutations in keratins
There are many different keratin proteins normally expressed in the human integumentary system. Mutations in keratin proteins in the skin can cause disease.
Of note, other structural proteins in the epidermis of the skin that are closely re ...
References
External links
{{DEFAULTSORT:Naegeli-Franceschetti-Jadassohn syndrome
Genodermatoses
Rare diseases
Syndromes
Fingerprints
Autosomal dominant disorders