Genetic inheritance in tandem: Non-syndromic autosomal recessive congenital ichthyosis with beta-thalassaemia: A rare coincidence

Abstract

Ichthyosis belongs to the group of Mendelian disorders of cornification. Congenital ichthyosis is inherited as an autosomal recessive trait, so it is also known as autosomal recessive congenital ichthyosis (ARCI). ARCI is classified into two types: syndromic and non-syndromic ARCI. Non-syndromic ARCIs include lamellar ichthyosis, congenital ichthyosiform erythroderma and Harlequin ichthyosis. Syndromic-ARCI is associated with multisystemic involvement, which includes Netherton syndrome, Chanarin-Dorfman disease and others. Other systemic diseases associated with ichthyosis include Gaucher disease type II and hypothyroidism. Chanarin-Dorfman and Gaucher disease-II are additionally associated with hepatosplenomegaly (HSM) and anaemia. We describe a child of congenital ichthyosis with HSM and anaemia thought to be syndromic-ARCI, but diagnosed for beta-thalassaemia (b-thal) concurrently. An infant presented with peeling skin along with absent sweating since birth and recent onset paleness of the body. Examination revealed Ichthyosis (Lamellar-variant), severe pallor and HSM, raising the possibility of Chanarin-Dorfman syndrome and Gaucher’s disease. The investigation revealed an Erlenmeyer flask deformity of the knee, but no Gaucher’s cells were found in the bone marrow. In the absence of lipid vacuoles leaden leukocytes (Jordan’s anomaly), Chanarin-Dorfman disease was also ruled out. Haemoglobin (Hb) high-performance liquid chromatography revealed β-thal major, and both parents were traits, giving us the diagnosis, which was further confirmed by the next-generation gene sequencing for clinical exomes. This report was to highlight non-syndromic ARCI involving the CYP4F22 gene variant, which is a rare finding, and the association of such ichthyosis with β-thal major was an unexpected result. Genetic counselling was provided to the parents in light of the autosomal recessive nature of both diseases. Genes of congenital ichthyosis and β-thal were unrelated, but simultaneous expressions of two autosomal-recessive diseases together are it merely by chance or a new entity.