A form of hypotonia-cystinuria syndrome characterized by mild to moderate intellectual disability in addition to classic hypotonia-cystinuria syndrome phenotype (cystinuria type 1, generalized hypotonia, poor feeding, growth retardation, and minor facial dysmorphism). The disease is MONDO_0016539 (atypical hypotonia-cystinuria syndrome). Also known as: atypical HCS.