GHRHR and isolated congenital growth hormone deficiency: In Itabaianinha County, in Northeast Brazil, we identified a large cohort of individuals with severe isolated GH deficiency (IGHD) caused by the null homozygous (c.57 + 1 A → G) mutation in the growth hormone releasing hormone (GHRH) receptor gene (GHRHR) (Salvatori et al., 1999).