Naegeli-Franceschetti-Jadassohn (NFJ) syndrome is a rare autosomal dominant form of ectodermal dysplasia that affects the skin, sweat glands, nails, and teeth. The incidence is estimated to be 1 case in 2-4 million population. NFJ syndrome is entry 161000 in the Online Mendelian Inheritance in Man database. The syndrome is allelic to dermatopathia pigmentosa reticularis.
In 1927, Naegeli first described the syndrome as familiärer Chromatophoren-Naevus in a Swiss family. In 1954, Franceschetti and Jadassohn further analyzed the syndrome, as did Itin and colleagues in 1993.
NFJ syndrome is a reticulate pigmentary disorder. Other reticulate pigmentary diseases include X-linked reticulate pigmentary disorder, dermatopathia pigmentosa reticularis, Dowling-Degos disease, dyschromatosis, confluent and reticulated papillomatosis of Gougerot and Carteaud, and reticulated acropigmentation of Kitamura.
Franceschetti and Jadassohn distinguished Naegeli syndrome from incontinentia pigmenti (Bloch-Sulzberger syndrome) by the equal frequency of the disorder in males and females and by the presence of palmar and plantar hyperkeratosis, hypohidrosis, and dental abnormalities. In contrast, incontinentia pigmenti is inherited as an X-linked dominant trait.
Dermatopathia pigmentosa reticularis, allelic to NFJ, shares many features and may be a variation of the same genetic defect, but is distinguished by alopecia, reticulate pigmentation that lasts into adulthood, and the lack of dental abnormalities.  Dyskeratosis congenita patients can have dental findings, reticulate hyperpigmentation, adermatoglyphia, palmoplantar hyperkeratosis, and nail anomalies similar to NFJ patients. However, these patients may have alopecia, premalignant leukoplakia, poikiloderma, and blood dyscrasias and dyskeratosis congenita is inherited most commonly in an X-linked recessive manner.
The distribution of the reticulate pigmentation in Dowling-Degos, dyschromatosis symmetrica and hereditaria, and reticulate acropigmentation of Kitamura makes these disorders easier to distinguish. 
Hereditary bullous acrokeratotic poikiloderma of Weary-Kindler has some striking similarities to NFJ syndrome. However, hypohidrosis is not reported with this entity, and dental abnormalities are only rarely observed. 
Naegeli-Franceschetti-Jadassohn (NFJ) syndrome may be associated with a number of markers located in the vicinity of the type I keratin gene cluster on band 17q21 (see Causes).
Naegeli-Franceschetti-Jadassohn (NFJ) syndrome is rare.
The estimated incidence of Naegeli-Franceschetti-Jadassohn (NFJ) syndrome is approximately 1 case in 2-4 million population.
Several families with Naegeli-Franceschetti-Jadassohn (NFJ) syndrome have been reported in Switzerland, Japan, Italy, Greece, and Saudi Arabia. There has also been one case report of a woman of Dutch descent and a case report of a man from India.
No sexual predilection is recognized for Naegeli-Franceschetti-Jadassohn (NFJ) syndrome.
Because of the inability to sweat, Naegeli-Franceschetti-Jadassohn (NFJ) syndrome is usually diagnosed early in life. The lack of fingerprint lines (ie, dermatoglyphics) can be easily checked.