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.

References

External links