Hereditary twenty-nail dystrophy in a Sicilian family

Trachyonychia: Review and Update on Clinical Aspects, Histology, and Therapy

Trachyonychia is a disorder of the nail unit that most commonly presents with rough, longitudinally ridged nails (opaque trachyonychia) or less frequently, uniform, opalescent nails with pits (shiny trachyonychia). The term trachyonychia refers to 'rough nails.' This article comprehensively reviews the clinical, histologic, and therapeutic aspects of trachyonychia. The authors' preferred evaluation and management strategies of trachyonychia are included.

Twenty nail dystrophy trachyonychia: An overview

Twenty nail dystrophy (TND) trachyonychia, a fascinating clinical condition, was brought to focus 25 years ago. Ever since, it has been sparingly reported. Nonetheless, the condition is well-recognized and its diagnosis is made on the basis of clinical features characterized by onset in infancy/childhood, and occasionally in adults. The lesions are fairly representative, and are characterized by the alternating elevation and depression (ridging) and/or pitting, lack of luster, roughening likened to sandpaper, splitting, and change to a muddy grayish-white color. Dystrophy is prominent. Several modes of occurrence have been described including an hereditary component. The confirmation of diagnosis is through microscopic pathology corresponding either to endogenous eczema/dermatitis, lichen-planus like or psoriasic-form. It is a self-limiting condition and may occasionally require intervention.

Localization of a novel locus for hereditary nail dysplasia to chromosome 17q25.1-17q25.3

We report on a six-generation Pakistani consanguineous family with autosomal recessive transmission of a form of hereditary nail dysplasia. Affected individuals presented with onycholysis of fingernails and anonychia of toenails. Associated abnormalities of ectodermal appendages were not observed in any of the affected individuals. Linkage has been established to chromosome 17q. A maximum multipoint analysis logarithm of the odds ratio score of 4.85 was obtained at marker D17S1301. Due to the consanguineous nature of this kindred, the gene for nail dysplasia is probably contained within a 5.0-cM (3 MB on the sequence-based physical map) region of homozygosity flanked by markers D17S1807 and D17S937.

Twenty-nail dystrophy in a mother and her 7-year-old daughter associated with balanced translocation 46, XX, t(6q13;10p13)

Twenty-nail dystrophy (TND) is an autosomal dominantly inherited idiopathic nail dystrophy characterized by excessive longitudinal striations and numerous superficial pits on nails with a typical 'sand papered' rough appearance. It is evident at birth and progresses slowly. It can also be associated with various diseases including lichen planus, alopecia areata, eczema, vitiligo and psoriasis. Peripheral blood chromosome analysis has not been performed in previously reported cases of TND. We report a mother and her 7-year-old daughter with TND. Both of them had a balanced translocation 46, XX, t(6q13;10p13). This may be a coincidental finding or may be related to the gene locus of TND.

Assignment of the gene for a new hereditary nail disorder, isolated congenital nail dysplasia, to chromosome 17p13

Isolated congenital nail dysplasia is an autosomal dominant disorder recently observed in a large family from southern Germany. The disorder is characterized by longitudinal streaks, thinning, and impaired formation of the nail plates leading to increased vulnerability of the free nail margins. In most cases, all fingernails and toenails are similarly involved with some accentuation of the thumb and great toenails. Histologic changes include hypergranulosis of the nail matrix and epithelial outgrowths from the nail bed. Patients do not show any alterations of hair growth and dentition, no malfunction of sweat glands and sensory organs, and no skeletal abnormalities. Isolated congenital nail dysplasia manifests from the first year of life with variable expressivity. In order to localize chromosomally the gene underlying isolated congenital nail dysplasia, linkage to the known keratin gene cluster regions on chromosomes 12q12 and 17q21 was ruled out first. The analysis of 150 microsatellite markers on various chromosomes mapped the isolated congenital nail dysplasia gene to the 6 cM interval between markers at D17S926 and D17S1528 on chromosome 17p13. Markers at D17S849, D17S 1840, and D17S1529 co-segregated completely with the isolated congenital nail dysplasia locus. The maximum two-point LOD score was found for the marker at D17S 1840 (Zmax = 6.72 at Thetamax = 0.00). The identified region harbors no currently known genes involved in skin or nail abnormalities. Isolated congenital nail dysplasia probably represents a novel isolated defect of nail development. The localization of this gene is, therefore, the first step towards the identification of a new factor in nail formation.

Idiopathic trachyonychia (twenty-nail dystrophy): a pathological study of 23 patients

We report the clinical features and pathological findings in 23 patients with idiopathic trachyonychia (twenty-nail dystrophy). Clinically, the nail changes in the majority of patients consisted of the typical 'sandpapered' appearance, with a rough, lustreless nail plate. In some, however, the nail plate abnormality was less severe, with numerous small, superficial pits, which imparted a shiny appearance to the surface of the nail. Histology of nail biopsy specimens showed spongiotic changes in 19 patients, psoriasiform features in three, and features of lichen planus in one patient. The mean follow-up of these patients was 2 years, during which time none developed alopecia areata or mucocutaneous lesions. Idiopathic trachyonychia is therefore a consequence of several inflammatory disorders, which produce a disturbance of nail matrix kinetics. The course of the inflammation and the extent of the inflammatory process within the nail matrix produce two different patterns of nail plate surface abnormalities.

Twenty nail dystrophy in identical twins

Twelve-year-old identical female twins have had lifelong twenty nail dystrophy. There is no evidence of other skin disorders. The condition has remained unchanged and has been unresponsive to a wide range of therapies. The benign clinical course of their nail disorder suggests twenty nail dystrophy may not be related to lichen planus or other cutaneous diseases. One of the causes of twenty nail dystrophy of childhood may be a localized tissue malformation, analogous to inflammatory linear verrucous epidermal naevus.

A new nail dysplasia syndrome with onychonychia and absence and/or hypoplasia of distal phalanges

A family in which two generations have a rare and previously undescribed form of nail dysplasia with bone abnormalities is reported. This disorder is characterized by onychodystrophy, anonychia, brachydactyly of the fifth digit of the hands, and digitalization of the thumbs, with absence and/or hypoplasia of the distal phalanges of the hands and feet. The probable mode of transmission is autosomal dominant.

Twenty-nail dystrophy of childhood: a sign of localized lichen planus

A 9 1/2-year-old girl was seen with 20-nail dystrophy. Lichen planus was suspected and further examination revealed other lesions localized to the oral mucosa. The diagnosis was confirmed as lichen planus by biopsy of tissue from the oral lesions. Careful examination of all mucocutaneous surfaces is recommended before accepting the diagnosis of so-called isolated 20-nail dystrophy of childhood.