Acro–dermato–ungual–lacrimal–tooth syndrome (ADULT syndrome) is a rare genetic disease. It is an
autosomal dominant
In genetics, dominance is the phenomenon of one variant (allele) of a gene on a chromosome masking or overriding the effect of a different variant of the same gene on the other copy of the chromosome. The first variant is termed dominant and t ...
form of
ectodermal dysplasia
Ectodermal dysplasia (ED) is a group of genetic syndromes all deriving from abnormalities of the ectodermal structures.James, William; Berger, Timothy; Elston, Dirk (2005). ''Andrews' Diseases of the Skin: Clinical Dermatology''. (10th ed.). Sau ...
, a group of disorders that affects the hair, teeth, nails, sweat glands, and extremities. The syndrome arises from a mutation in the
TP63
Tumor protein p63, typically referred to as p63, also known as transformation-related protein 63 is a protein that in humans is encoded by the ''TP63'' (also known as the '' p63'') gene.
The ''TP63'' gene was discovered 20 years after the discove ...
gene. This disease was previously thought to be a form of
ectrodactyly–ectodermal dysplasia–cleft syndrome
Ectrodactyly–ectodermal dysplasia–cleft syndrome, or EEC, and also referred to as EEC syndrome and split hand–split foot–ectodermal dysplasia–cleft syndromeFreedberg, et al. (2003). ''Fitzpatrick's Dermatology in General Medicine''. (6th ...
(EEC), but was classified as a different disease in 1993 by
Propping and Zerres.
Signs and symptoms
ADULT syndrome features include
ectrodactyly
Ectrodactyly, split hand, or cleft hand (derived from Greek ''ektroma'' 'abortion' and ''daktylos'' 'finger') involves the deficiency or absence of one or more central digits of the hand or foot and is also known as split hand/split foot malformat ...
,
syndactyly
Syndactyly is a condition wherein two or more digits are fused together. It occurs normally in some mammals, such as the siamang and diprotodontia, but is an unusual condition in humans. The term is from Greek σύν, ''syn'' 'together' and δάκ ...
, excessive
freckling
Freckles are clusters of concentrated melaninized cells which are most easily visible on people with a fair complexion. Freckles do not have an increased number of the melanin-producing cells, or melanocytes, but instead have melanocytes that ...
,
lacrimal duct
The lacrimal canaliculi, (sing. canaliculus), are the small channels in each eyelid that drain lacrimal fluid, from the lacrimal puncta to the lacrimal sac. This forms part of the lacrimal apparatus that drains lacrimal fluid from the surface of ...
anomalies,
dysplastic
Dysplasia is any of various types of abnormal growth or development of cells (microscopic scale) or organs (macroscopic scale), and the abnormal histology or anatomical structure(s) resulting from such growth. Dysplasias on a mainly microscopic ...
nails,
hypodontia
Hypodontia is defined as the developmental absence of one or more teeth excluding the third molars. It is one of the most common dental anomalies, and can have a negative impact on function, and also appearance. It rarely occurs in primary teet ...
,
hypoplastic
Hypoplasia (from Ancient Greek ὑπo- ''hypo-'' 'under' + πλάσις ''plasis'' 'formation'; adjective form ''hypoplastic'') is underdevelopment or incomplete development of a tissue or organ.hypotrichosis
Hair loss, also known as alopecia or baldness, refers to a loss of hair from part of the head or body. Typically at least the head is involved. The severity of hair loss can vary from a small area to the entire body. Inflammation or scarri ...
,
hypohidrosis
Hypohidrosis is a disorder in which a person exhibits diminished sweating in response to appropriate stimuli. In contrast with hyp''er''hidrosis, which is a socially troubling yet often benign condition, the consequences of untreated hypohidrosi ...
, broad
nasal bridge
The nasal bridge is the upper, bony part of the human nose, which overlies the nasal bones.
Association with epicanthic folds
Low-rooted nasal bridges are closely associated with epicanthic folds. A lower nasal bridge is more likely to cause an ...
, midfacial hypoplasia,
exfoliative dermatitis, and
xerosis
Xeroderma, xerosis or xerosis cutis, or simply dry skin, is a skin condition characterized by excessively dry skin.
The medical term ''xeroderma'', meaning "dry skin", derives from modern Latin, ''xero-'' 'dry' + Greek ''derma'' 'skin'.
In most ...
. The lack of
facial cleft A facial cleft is an opening or gap in the face, or a malformation of a part of the face. Facial clefts is a collective term for all sorts of clefts. All structures like bone, soft tissue, skin etc. can be affected. Facial clefts are extremely rare ...
ing and
ankyloblepharon
Ankyloblepharon is defined as the adhesion of the edges of the upper eyelid with the lower eyelid. Ankyloblepharon must be differentiated from blepharophimosis, in which palpebral aperture is reduced and there is telecanthus, but the eyelid margins ...
are important because they exist in
ectrodactyly–ectodermal dysplasia–cleft syndrome
Ectrodactyly–ectodermal dysplasia–cleft syndrome, or EEC, and also referred to as EEC syndrome and split hand–split foot–ectodermal dysplasia–cleft syndromeFreedberg, et al. (2003). ''Fitzpatrick's Dermatology in General Medicine''. (6th ...
(EEC) but not in ADULT syndrome.
Cause
ADULT syndrome is due to autosomal dominant mutations of the
TP63
Tumor protein p63, typically referred to as p63, also known as transformation-related protein 63 is a protein that in humans is encoded by the ''TP63'' (also known as the '' p63'') gene.
The ''TP63'' gene was discovered 20 years after the discove ...
gene, which encodes the p63 protein. TP63 mutations cause deformities because the p63 protein is critical in embryonic development of limbs and other
ectoderm
The ectoderm is one of the three primary germ layers formed in early embryonic development. It is the outermost layer, and is superficial to the mesoderm (the middle layer) and endoderm (the innermost layer). It emerges and originates from t ...
al tissues. 7 mutations have been found, the commonest forms being R298Q and R243W, in which encoding for arginine is changed to glutamine at position 298 and tryptophan at position 243 respectively.
[
] Other p63 genes mutation syndromes include
ectrodactyly–ectodermal dysplasia–cleft syndrome
Ectrodactyly–ectodermal dysplasia–cleft syndrome, or EEC, and also referred to as EEC syndrome and split hand–split foot–ectodermal dysplasia–cleft syndromeFreedberg, et al. (2003). ''Fitzpatrick's Dermatology in General Medicine''. (6th ...
(EEC) and
Hay-Wells syndromes.
Diagnosis
Treatment
References
External links
Rare syndromes
Genodermatoses
{{genetic-disorder-stub