Lamellar ichthyosis associated with pseudoainhum of the toes and eye changes

Nail Involvement in Autosomal Recessive Congenital Ichthyosis

Autosomal recessive congenital ichthyosis (ARCI) is a clinically and genetically heterogeneous category of non-syndromic ichthyosis (2). Nail changes in ARCI are generally frequent but have been rarely reported and studied in the literature. This stimulated us to conduct a study to describe nail changes in ARCI using a combined literature review and prospective examination from March 2019 to August 2019 (6 months) in the Dermatology Department of Habib Thameur Hospital, Tunis, Tunisia. A total of twenty-five patients with ARCI had a clinical and dermatoscopic review. Mean age was 19.8 years old [range 1-43], with a female predominance- 17 women (68%) and 8 men (32%). Seventy-two percent had nail unit changes involving more than one nail, none with single nail disease, involvement of fingernails (64%) and toenails (68%) cases including periungual hyperkeratosis (64%), xanthonychia (40%), pachyonychia (40%), macrolunula (36%), digital clubbing (32%) and onychomycosis (24%). Rarer findings included pseudoainhum, transverse leukonychia, longitudinal melanonychia, and subungual hemorrhages each in one patient (4%). There was a statistically significant increased frequency of nail changes in adults over children (p = 0.001). Nail abnormalities statistically associated with ARCI were macrolunula, periungual hyperkeratosis, xanthonychia, and pachyonychia. A comprehensive review of the literature was performed, creating the first comprehensive review addressing nail disease in ARCI.

Fibroblast apoptosis in a patient affected by lamellar ichthyosis

BACKGROUND

Lamellar ichthyosis (LI) is a congenital recessive skin disorder characterized by generalized scaling and hyperkeratosis. The pathology may be caused by mutations in transglutaminase 1 (TGM1) gene that encodes an enzyme critical for terminally differentiating keratinocytes. Because of evidences that transglutaminase enzymes are involved in programmed cell death, we investigated morphological and biochemical apoptotic parameters in cultured skin fibroblasts from a patient with a severe LI and homozygous for the TGM1 R142H mutation.

METHOD

The principle apoptotic signals (mitochondrial membrane potential, analysis of oxygen consumption, DNA fragmentation and Bax/Bcl-2 gene expression) were analyzed in cultured fibroblasts from a LI patient, his mother (TGM1 mutation carrier) and a control subject.

RESULTS

LI fibroblasts showing a reduction of fibronectin expression evidenced a strong inhibition of oxygen consumption, a dramatic drop in the mitochondrial membrane potential (Delta psi(m)), and a higher apoptotic index.

CONCLUSION

The present results suggest a possible connection between the alterations in the keratinization process leading to LI and the observed increased fibroblast apoptosis.

Transcriptional profiles of unirradiated or UV-irradiated human cells expressing either the cancer-prone XPB/CS allele or the noncancer-prone XPB/TTD allele

Xeroderma pigmentosum (XP) and trichothiodystrophy (TTD) syndromes are characterized by deficiency in nucleotide excision repair pathway, but with distinguished clinical manifestations. While XP patients exhibit a high frequency of skin cancer, TTD patients are not cancer prone. The relation between lack of DNA repair and their clinical manifestations was investigated through analysis of the transcriptional profile of 12,600 transcripts in two isogenic cell lines with different capabilities of DNA repair. These cell lines result from a stable transfection of the XPB-TTD allele into XP complementation group B fibroblasts, from an XP patient who also have clinical abnormalities corresponding to Cockayne's syndrome (CS). The microarray assays performed under normal growth conditions showed the expression of distinct groups of genes in each cell line. The UVC-transcription modulation of these cells revealed the changes in 869 transcripts. Some of these transcripts had similar modulation pattern in both cells, although with eventually different time patterns for induction or repression. However, some different 'UVC signature' for each cell line was also found, that is, transcripts that were specifically UV regulated depending on the DNA repair status of the cell. These results provide a detailed portrait of expression profiles that may potentially unravel the causes of the different phenotypes of XP/CS and TTD patients.