Case report of individual with cutaneous immunodeficiency and novel 1p36 duplication

Crusted or Norwegian scabies is an infectious skin dermatopathology usually associated with an underlying immunodeficiency condition. It is caused when the mite Sarcoptes scabiei infects the skin, and the immune system is unable to control its spread, leading to a massive hyperinfestation with a simultaneous inflammatory and hyperkeratotic reaction. This is the first report of a novel 1p36 duplication associated with a recurrent infection of crusted scabies.

We describe a 34-year-old patient with a cutaneous immunodeficiency characterized by recurrent crusted scabies infestation, diffuse tinea, and recurrent staphylococcal cellulitis, who we suspected had an undiagnosed syndrome. The patient also suffered from mental retardation, renal failure, and premature senescence. A cytogenetic fluorescence in situ hybridization analysis revealed a 9.34 Mb duplication within the short (p) arm of chromosome 1, precisely from 1p36.11 to 1p36.21, with an adjacent 193 kb copy gain entirely within 1p36.11. In addition, chromosome 4 had a 906 kb gain in 4p16.1 and chromosome 9 had a 81 kb copy gain in 9p24.3. Over 100 genes localized within these duplicated regions. Gene expression array revealed 82 genes whose expression changed >1.5-fold compared to a healthy age-matched skin control, but among them only the lipolytic enzyme arylacetamide deacetylase-like 3 was found within the duplicated 1p36 region of chromosome 1.

Although genetic duplications in the 1p36 region have been previously described, our report describes a novel duplicative variant within the 1p36 region. The patient did not have a past history of immunosuppression but was afflicted by a recurrent case of crusted scabies, raising the possibility that the recurrent infection was associated with the 1p36 genetic duplication.

To our knowledge, the specific duplicated sequence between 1p36.11 and p36.21 found in our patient has never been previously reported. We reviewed and compared the clinical, genotyping, and gene microarray results of our patient in order to characterize this novel 1p36 duplication syndrome, which might have contributed to the recurrent scabies infection in this patient.