A particular subtype of ichthyosis congenita type III. Clinical, light, and electron microscopic features

Autosomal recessive congenital ichthyosis

The term autosomal recessive congenital ichthyosis (ARCI) refers to a group of rare disorders of keratinization classified as nonsyndromic forms of ichthyosis. This group was traditionally divided into lamellar ichthyosis (LI) and congenital ichthyosiform erythroderma (CIE) but today it also includes harlequin ichthyosis, self-healing collodion baby, acral self-healing collodion baby, and bathing suit ichthyosis. The combined prevalence of LI and CIE has been estimated at 1 case per 138 000 to 300 000 population. In some countries or regions, such as Norway and the coast of Galicia, the prevalence may be higher due to founder effects. ARCI is genetically highly heterogeneous and has been associated with 6 genes to date: TGM1, ALOXE3, ALOX12B, NIPAL4, CYP4F22, and ABCA12. In this article, we review the current knowledge on ARCI, with a focus on clinical, histological, ultrastructural, genetic, molecular, and treatment-related aspects.

[Cutaneous fissures in collodion babies: incidence and treatment]

BACKGROUND

Collodion baby syndrome (CBS) is a pathological cutaneous condition present at birth and is due to the presence of a thick horny layer of the skin. Exfoliation begins early with drying and cracking of the collodion membrane. The cracks may either remain superficial or they may be deeper and affect the superficial dermis, in which case, fissures form. This study of CBS provides information on the clinical aspect of fissures, their incidence, their pathological consequences and therapeutic approaches.

PATIENTS AND METHODS

In our study, diagnosis of CBS was made clinically based on the presence of neonatal collodion membrane. Identification of typical cracks and fissures was made on clinical examination and their site, chronology and consequences were assessed. Routine bacteriological examination of fissures was performed twice weekly on a clinically infected specimen taken from an inguinal fissure. The therapeutic protocol for CBS has been validated and involved use of sterile vaseline oil. Fissures were disinfected.

RESULTS

Cracks are a constant feature. Fissures were seen in 20 of the 33 cases of CBS with the site of predilection being large skinfolds. Morphine was necessary for pain relief in three cases. Pathogenic organisms were isolated in all cases of inflammatory fissures. Dissemination of septicaemia was confirmed in four cases and the offending organism was isolated from the inflammatory fissures in all cases. Candida albicans was present in all cases of fissures in the inguinal folds or between the buttocks. Keratotic adhesions occurred after healing of digital fissures and a surgical procedure was required in this event.

DISCUSSION

Fissures are lesions occurring secondarily to cracks and they were seen in 20 of the 33 cases of CBS. These secondary lesions are rarely mentioned in the literature and the reasons for this oversight are discussed. Fissures are potential complications in all states of CBS, particularly where the collodion is thick. Topical treatment does not prevent transformation of cracks to fissures in all cases. Where fissures are not inflammatory, routine prescription of oral antibiotics is not always necessary. Regular bacteriological monitoring at several different fissure sites allows selection of appropriate antibiotic therapy. The main therapeutic goal in CBS is to treat painful fissures and superinfection.

The clinical spectrum of nonbullous congenital ichthyosiform erythroderma and lamellar ichthyosis

Until about 20 years ago, the term lamellar ichthyosis (LI) represented all nonbullous autosomal recessive ichthyoses except for harlequin ichthyosis and ichthyosis syndromes. Since the 1980s, nonbullous autosomal recessive ichthyoses have been divided into two major clinical entities, nonbullous congenital ichthyosiform erythroderma (NBCIE) and LI. The nature of scaling and intensity of erythroderma are important clinical features that distinguish between NBCIE and LI. However, a considerable number of cases show an intermediate phenotype between the two classic clinical features. Histologically, parakeratosis and inflammatory cell infiltration are seen more frequently in NBCIE than in LI and the stratum corneum is usually thicker in LI than in NBCIE. However, neither histopathological findings nor ultrastructural features seem to help clearly distinguish between NBCIE and LI. Mutations in any of the three known causative genes, TGM1, ALOXE3 or ALOX12B, can lead either to NBCIE or LI. Candidate genes specific to either NBCIE or LI alone have not been identified. Based on these facts, it might be better to consider NBCIE and LI as variations of a single keratinization disorder, although the classification of these autosomal recessive congenital ichthyosis patients into NBCIE or LI depending on their clinical features is still useful for practical patient management.

The spectrum of pathogenic mutations in SPINK5 in 19 families with Netherton syndrome: implications for mutation detection and first case of prenatal diagnosis

The Comèl-Netherton syndrome is an autosomal recessive multisystemic disorder characterized by localized or generalized congenital ichthyosis, hair shaft abnormalities, immune deficiency, and markedly elevated IgE levels. Life-threatening complications during infancy include temperature and electrolyte imbalance, recurrent infections, and failure to thrive. To study the clinical presentations of the Comèl-Netherton syndrome and its molecular cause, we ascertained 19 unrelated families of various ethnic backgrounds. Results of initial linkage studies mapped the Comèl-Netherton syndrome in 12 multiplex families to a 12 cM interval on 5q32, thus confirming genetic homogeneity of Comèl-Netherton syndrome across families of different origins. The Comèl-Netherton syndrome region harbors the SPINK5 gene, which encodes a multidomain serine protease inhibitor (LEKTI) predominantly expressed in epithelial and lymphoid tissues. Recently, recessive mutations in SPINK5 were identified in several Comèl-Netherton syndrome patients from consanguineous families. We used heteroduplex analysis followed by direct DNA sequencing to screen all 33 exons and flanking intronic sequences of SPINK5 in the affected individuals of our cohort. Mutation analysis revealed 17 distinct mutations, 15 of which were novel, segregating in 14 Comèl-Netherton syndrome families. The nucleotide changes included four non-sense mutations, eight small deletions or insertions leading to frameshift, and five splice site defects, all of which are expected to result in premature terminated or altered translation of SPINK5. Almost half of the mutations clustered between exons 2 and 8, including two recurrent mutations. Genotype-phenotype correlations suggested that homozygous nucleotide changes resulting in early truncation of LEKT1 are associated with a severe phenotype. For the first time, we used molecular data to perform prenatal testing, thus demonstrating the feasibility of molecular diagnosis in the Comèl-Netherton syndrome.