Keratitis, Ichthyosis, and Deafness (KID) Syndrome in Half Sibs

Abstract

The keratitis, ichthyosis, and deafness (KID) syndrome is a rare congenital disorder of the ectoderm characterized by diffuse hyperkeratotic erythroderma, keratitis with neovascularization of the cornea, and severe neurosensory hearing loss. A familial occurrence of this syndrome has been mentioned in four reports including three of vertical transmission and one of two affected sisters born from consanguineous, unaffected parents. We report for the first time a familial case of KID syndrome in two half siblings born to the same unaffected mother. This new observation allows us to propose various hypotheses about its mode of inheritance.The keratitis, ichthyosis, and deafness (KID) syndrome, so-called by Skinner et al. in 1981 (l), is a rare disorder including an extensive hyperkeratotic eruption, neurosensory deafness, and keratitis with neovascularization of the cornea. It is a congenital ectodermal disorder without a clear mode of inheritance. However, three previous reports of vertical transmission have suggested a dominant pattern of transmission ( 2 4 ) . In contradiction of this speculation are the cases of two sisters born of consanguineous parents (cousins four generations before) which are suggestive of recessive transmission (5). We report herein for the first time a familial case of KID syndrome affecting two half siblings (same unaffected mother) of different sex. This new observation allows us to exclude the possibility of an Xchromosomal recessive mode of inheritance. CASE REPORTS Patient 1A 5-year-old black boy was referred for an extensive chronic pruritic hyperkeratotic dermatosis. He was born to unrelated healthy parents (Malagasy mother with dark skin and Comorian father with pale skin) after a full-term pregnancy and normal delivery. Skin lesions began at the age of 3 months and his hair was lost by 6 months. At his first physical examination in our unit he had multiple vermcoid lesions, diffuse ichthyosis with palmoplantar keratoderma, and total alopecia including the scalp, eyebrows, and eyelashes (Figs. 1, 2). A hard crust was present on his scalp and nipples; moreover, his skin was thickened and hyperkeratotic over the cheeks, knees and elbows, as well as his perineum and extremities. The palms and soles showed a reddish orange keratoderma. His nails were dystrophic, with both leukonychia and hypertrophy. He had moderate growth retardation (-2 SD) and his development was impaired by sensory handicaps including complete deafness and severe loss of visual acuity with permanent photophobia. An audiogram indicated neurosensory deafness. The ophthalmoscopic examination disclosed a thickened, almost opaque corneal epithelium with superficial neovascularization and linear opacities. Histologic findings on specimens from venucoid hyperkeratotic areas of the integument

Connexin 26 (GJB2) mutations, causing KID Syndrome, are associated with cell death due to calcium gating deregulation

“…The autosomic dominant KID Syndrome (MIM 148210), caused by mutations in GJB2 (connexin 26, Cx26), [1] or GJB6 (connexin 30.3, Cx30.3) [2,3], is an ectodermal dysplasia which is normally included in the heterogeneous group of the erythrokeratodermias. At epidermal level, KID Syndrome shows localized erythematous scaly lesions and keratitis [4][5][6][7][8][9][10][11][12][13][14], with occasional scarring alopecia, while severe sensorineural deafness is evident at the hearing level. Further diagnostic features include corneal epithelial defects, scarring, and neo-vascularisation that could progress to blindness.…”

Successful cochlear implantation in a child with Keratosis, Icthiosis and Deafness (KID) Syndrome and Dandy-Walker malformation

“…Although most cases of KID Syndrome, including the current case, are sporadic, familial occurrence of KID Syndrome can occur [8]. There are a total of 5 cases of familial occurrence in the literature, with 3 reports in 4 families suggesting autosomal dominant transmission [20][21][22] and a single report suggesting autosomal recessive transmission [19].…”

Keratitis‐ichthyosis‐deafness (KID) syndrome with squamous cell carcinoma

“…Koné‐Paut et al. 11 described two affected half‐siblings of different gender, children of an unaffected mother and different unaffected fathers, where there was a high level of consanguinity. Heterozygous missense mutations in the connexin‐26 gene, GJB2, have been found in a study of ten subjects 22 .…”