Background

Ichthyosis bullosa of Siemens (IBS) is a rare hyperkeratotic blistering condition caused by mutations in keratin 2e gene.

Main observations

This is a case of a 18-year-old female with generalized blisters, erosions and thickened skin since she was 3 months old. As she aged, there was decrease in development of blisters and erosions, with accompanying increase in severity of hyperkeratosis. Skin punch biopsy showed overlying basket weave hyperkeratosis and acanthosis, prominent vacuolization of the granular cell layer, and intraepidermal blisters with the split at the granular layer. The patient was treated with emollients, with marked improvement.

Conclusions

Mutations in the different keratin genes have been shown to underlie a wide range of disorders of keratinization. Epidermolytic hyperkeratosis and ichthyosis bullosa of Siemens are distinct disorders with mutations in different genes. Although molecular genetic testing should ideally be done for confirmation of diagnosis, ichthyosis bullosa of Siemens could be diagnosed in this patients based on key clinical characteristics.

To identify genes involved in phenotypic traits, translational genomics from highly characterized model plants to poorly characterized crop plants provides a valuable source of markers to saturate a zone of interest as well as functionally characterized candidate genes. In this paper, an integrated view of the pea genetic map was developed. A series of gene markers were mapped and their best reciprocal homologs were identified on M. truncatula, L. japonicus, soybean, and poplar pseudomolecules. Based on the syntenic relationships uncovered between pea and M. truncatula, 5460 pea Unigenes were tentatively placed on the consensus map. A new bioinformatics tool, http://www.thelegumeportal.net/pea_mtr_translational_toolkit, was developed that allows, for any gene sequence, to search its putative position on the pea consensus map and hence to search for candidate genes among neighboring Unigenes. As an example, a promising candidate gene for the hypernodulation mutation nod3 in pea was proposed based on the map position of the likely homolog of Pub1, a M. truncatula gene involved in nodulation regulation. A broader view of pea genome evolution was obtained by revealing syntenic relationships between pea and sequenced genomes. Blocks of synteny were identified which gave new insights into the evolution of chromosome structure in Papillionoids and Eudicots. The power of the translational genomics approach was underlined.