Dear Editor, Autosomal recessive congenital ichthyosis (ARCI) is an umbrella term for inherited nonsyndromic ichthyosis, which includes harlequin ichthyosis, lamellar ichthyosis (LI), congenital ichthyosiform erythroderma and pleomorphic ichthyosis (also called self-healing/self-improving collodion baby). 1 The clinical diversity is matched by genetic heterogeneity, with 11 genes currently implicated in the pathobiology of ARCI, 2, 3 including the most recent discovery of two missense mutations in SDR9C7 in three consanguineous Lebanese families. 4 Here we describe a case of ARCI (LI phenotype) with a previously unreported homozygous deletion mutation in SDR9C7. We extend the spectrum of clinical features associated with SDR9C7 mutations and identify deficient intercellular lipid and malformation of intercellular lipid layers in the stratum corneum.

The patient is a 72-year-old Japanese woman, the youngest of 11 siblings born to nonrelated parents. At birth she was noticed to have collodion membrane and presented with symptoms of ichthyosis after birth. She was treated with systemic retinoid; however, it was ineffective and her scales got worse. Her other medical history included diabetes mellitus and hypertension. On examination, she had large, whitish to light brown scales without erythroderma on her trunk and extremities (Fig. 1a, b). There was palmoplantar keratoderma. She had no hair, nail, dental or mucosal abnormalities, and vision and hearing were normal. There was no family history of any skin disorder.