An isolated growth hormone deficiency characterized by autosomal recessive inheritance of severe dwarfism with onset by 6 months of age and variable development of antibodies to growth hormone following exogenous supplementation that has material basis in null mutations in the GH1 gene on chromosome 17q23.3. The disease is isolated growth hormone deficiency type IA (MONDO_0009876). Also known as: IGHD IA, Illig-type growth hormone deficiency, autosomal recessive isolated growth hormone deficiency, congenital IGHD type IA, congenital isolated GH deficiency type IA, congenital isolated growth hormone deficiency type IA, growth hormone deficiency, isolated, type IA, pituitary dwarfism I.