Congenital ichthyosis with hypogonadism and growth retardation--a new syndrome with peculiar ultrastructural features

A novel congenital ichthyosiform syndrome with associated panhypopituitarism, corneal opacities and mental retardation

A 15-year-old male presented with ichthyosis since infancy with panhypopituitarism, short stature and knock-knees, delayed puberty, high scrotal retractile testes, mental retardation and corneal opacities. He developed recurrent tinea capitis and tinea corporis. The clinical symptomatology indicates that this case cannot be considered as a subtype of inherited ichthyosis group, but suggests a new syndrome as a separate nosologic entity. Two previously reported cases with possibly the same syndrome also had ichthyosis associated with variable endocrinopathy. Thorough endocrinological evaluation and appropriate intervention in patients of ichthyosis with short stature may reduce the morbidity associated with retarded skeletal growth and gonadal maturation.

Epidermolytic hyperkeratosis: a keratin 1 or 10 mutational event

Epidermolytic hyperkeratosis is an unusual type of ichthyosis. This inherited keratinization disorder is characterized clinically by erythema, blistering, and peeling shortly after birth. It may resolve and be replaced with thick scaling. It can lead to life-threatening complications, such as sepsis. Histologically, there is a hyperkeratosis and vacuolar degeneration. Genetically, this is an autosomal dominant disease with complete penetrance; however, 50% are spontaneous mutations. The clinical phenotype is a result of alterations in the gene(s) for keratin 1 and/or 10. We review this disorder and its therapy, which is mainly symptomatic with emollients and retinoids.

Homozygosity mapping of a locus for a novel syndromic ichthyosis to chromosome 3q27-q28

Ichthyosis is a heterogeneous group of skin disorders characterized by abnormal epidermal scaling. Occasionally, extracutaneous features are associated. A novel autosomal recessive ichthyosis syndrome is described here with scalp hypotrichosis, scarring alopecia, sclerosing cholangitis, and leukocyte vacuolization in two inbred kindreds of Moroccan origin. We also report the mapping of the diseased gene to a 21.2 cM interval of chromosome 3q27-q28. Homo zygosity for polymorphic markers has enabled us to reduce the genetic interval to a 16.2 cM region. Furthermore, comparison of mutant chromosomes in the two families has suggested a common ancestral mutant haplotype. This linkage disequilibrium has reduced the genetic interval encompassing the diseased gene to less than 9.5 cM maximum. Further study of additional families from the same geographic area will hopefully reduce the genetic interval as well as help in the cloning of the gene involved in this rare disorder.

Ultrastructural identification of basic abnormalities as clues to genetic disorders of the epidermis

The present article discusses specific, directly gene-dependent ultrastructural markers of dominantly inherited epidermal disorders that serve as clues to their underlying molecular genetic abnormalities. These are epidermolysis bullosa simplex Koebner and Weber-Cockayne with rupture or non-assembly of basal cell keratins and point mutations in keratins 5 and 14. Clumping of basal cell keratins is pathognomonic of EB Dowling-Meara and caused by mutations in hot spots of the rod domain of K5 and K 14. Clumps and aggregates of basal keratins occur side by side in the same cell and thus do not indicate specific different types of mutations. Similar clumping of suprabasal keratins in bullous CIE Brocq and in palmoplantar keratoderma Voerner have been assigned to identical types of mutations in the same critical position of the rod domain in K 1, K 10, and K 9, respectively. Highly unusual tubular keratins are pathognomonic of another dominant palmoplantar keratoderma type the genetic basis of which still awaits elucidation. Shell formation of (low molecular weight?) keratins in ichthyosis hystrix Curth-Macklin is not linked to the keratin gene clusters on chromosomes 12 and 17 and might be related to regulatory genes of keratin expression. Suprabasal shells in congenital reticular ichthyosiform erythroderma do not consist of keratins but resemble glycoprotein networks. Finally, the keratohyalin abnormality in ichthyosis vulgaris was the clue for the identification of a filaggrin deficiency, at the same time giving evidence to the heterogeneity of keratohyalin proteins.