Article Text

other Versions

PDF
Original article
Mutation in KANK2, encoding a sequestering protein for steroid receptor coactivators, causes keratoderma and woolly hair
  1. Yuval Ramot1,2,
  2. Vered Molho-Pessach1,2,
  3. Tomer Meir3,
  4. Ruslana Alper-Pinus1,
  5. Ihab Siam1,
  6. Spiro Tams4,
  7. Sofia Babay2,
  8. Abraham Zlotogorski1,2
  1. 1Department of Dermatology, Hadassah—Hebrew University Medical Center, Jerusalem, Israel
  2. 2The Center for Genetic Diseases of The Skin and Hair, Hadassah—Hebrew University Medical Center, Jerusalem, Israel
  3. 3Department of Nephrology, Hadassah—Hebrew University Medical Center, Jerusalem, Israel
  4. 4Faculty of Medicine, The Palestinian Al Quds University, Abu Dis, The Palestinian Authority
  1. Correspondence to Professor Abraham Zlotogorski, Department of Dermatology, Hadassah—Hebrew University Medical Center, Jerusalem 9112001, Israel; zloto{at}cc.huji.ac.il

Abstract

Background The combination of palmoplantar keratoderma and woolly hair is uncommon and reported as part of Naxos and Carvajal syndromes, both caused by mutations in desmosomal proteins and associated with cardiomyopathy. We describe two large consanguineous families with autosomal-recessive palmoplantar keratoderma and woolly hair, without cardiomyopathy and with no mutations in any known culprit gene. The aim of this study was to find the mutated gene in these families.

Methods and results Using whole-exome sequencing, we identified a homozygous missense c.2009C>T mutation in KANK2 in the patients (p.Ala670Val). KANK2 encodes the steroid receptor coactivator (SRC)-interacting protein (SIP), an ankyrin repeat containing protein, which sequesters SRCs in the cytoplasm and controls transcription activation of steroid receptors, among others, also of the vitamin D receptor (VDR). The mutation in KANK2 is predicted to abolish the sequestering abilities of SIP. Indeed, vitamin D-induced transactivation was increased in patient's keratinocytes. Furthermore, SRC-2 and SRC-3, coactivators of VDR and important components of epidermal differentiation, are localised to the nucleus of epidermal basal cells in patients, in contrast to the cytoplasmic distribution in the heterozygous control.

Conclusions These findings provide evidence that keratoderma and woolly hair can be caused by a non-desmosomal mechanism and further underline the importance of VDR for normal hair and skin phenotypes.

Statistics from Altmetric.com

Request permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.