Keratitis-ichthyosis-deafness syndrome with lethal p.Ala88Val variant and severe hypercalcemia

Keratitis-ichthyosis-deafness (KID) syndrome is a rare genetic disease caused by pathogenic variants in connexin 26 (gene GJB2), which is part of the transmembrane channels of the epithelia. Connexin 26 is expressed mainly in the cornea, the sensory epithelium of the inner ear, and in the skin keratinocytes, which are the three main target organs in KID syndrome. Approximately a dozen pathogenic variants have been described to date, including some lethal forms. Patients with lethal pathogenic variants present with severe symptoms from birth and die from sepsis during the first year of life. We present a premature female patient with KID syndrome carrying the lethal p.Ala88Val pathogenic variant in GJB2. In addition to the respiratory distress associated with this variant, our patient presented severe hypercalcemia of unexplained origin refractory to treatment. This abnormality has not been reported earlier in other patients with KID syndrome with the same variant.