CNS-II is a rare autosomal recessive hereditary disease and is typically caused by rare homozygous or compound heterozygous mutations in UGT1A1. In some cases, CNS-II is caused by a combination of a heterozygous Crigler–Najjar-associated structural variant and a GS-associated variant in the promoter region of the gene (c.-40_-39insTA, rs3064744) [4]. The gene discussed is UGT1A1; the disease is autosomal recessive disease.