Ichthyosis Hystrix Gravior

Description

Anton-Lamprecht (1978) stated that 4 genetic disorders of keratinization are known to have a structural defect of tonofibrils. (1) In the harlequin fetus (242500), an abnormal x-ray diffraction pattern of the horn material points to a cross-beta-protein structure instead of the normal alpha-protein structure of keratin. (2) Bullous ichthyosiform erythroderma (EHK; 113800) is characterized by an early formation of clumps and perinuclear shells due to an abnormal arrangement of tonofibrils. (3) In the Curth-Macklin form of ichthyosis hystrix (146590), concentric unbroken shells of abnormal tonofilaments form around the nucleus. (4) In ichthyosis hystrix gravior, only rudimentary tonofilaments are found with compensatory production of mucous granules.

Goldsmith (1976) used the designation of epidermolytic hyperkeratosis for the condition that is called bullous congenital ichthyosiform erythroderma (BCIE) when generalized and ichthyosis hystrix when localized.

Clinical Features

Penrose and Stern (1958) stated that between 1731 and 1851, the Lambert family of Suffolk, England, had 11 members in 4 generations with ichthyosis hystrix gravior. It was the Lambert pedigree from which the term 'porcupine man' arose. In their review, Penrose and Stern (1958) showed that females in this family were also affected. The skin, normal at birth, developed dark warty scaling after 7 weeks of age. There was no blistering, and the face, palms, and soles were spared.

Epstein (1992) suggested that the disorder in the historic 'porcupine man' may have been bullous congenital ichthyosiform erythroderma.

Inheritance

Y-linkage was suggested on the basis of the famous Lambert pedigree. Penrose and Stern (1958) disproved this, however, and concluded that autosomal dominant inheritance is likely.

Diagnosis

Anton-Lamprecht (1978) pointed out that electron microscopy is particularly revealing in dominant disorders in which structural abnormality of a protein is likely to be found, whereas biochemistry is more likely to be revealing in recessive disorders. The examples he used from dermatology to illustrate electron microscopic abnormalities in dominant disorders were: structural defects of tonofibrils in hystrix-like ichthyoses, of the anchoring fibrils in dominant dystrophic epidermolysis bullosa of Pasini, and of keratohyalin in autosomal dominant ichthyosis vulgaris.