Victor A. McKusick, OMIM, Johns Hopkins University, June 24, 2004
[for Professionals mainly]
The African pygmy fails to respond to exogenous hormone in the presence of normal serum levels of growth hormone and of somatomedin ... Thus, the 'defect' appears to involve end-organ responsiveness to somatomedin ... The genetics of the change is unclear. Merimee et al. (1981) demonstrated isolated deficiency of insulinlike growth factor I (IGF-I) in pygmies of the Central African Republic and proposed that this is the gene-determined basis of growth deficiency ... Daughaday et al. (1972) coined the term 'somatomedin.' ... shown to have insulin like activity ... African pygmies in Zaire ... found that perpubertal pygmy children and controls did not differ in linear growth ... There was a significant difference in growth between controls and pygmies only during puberty ...
Victor A. McKusick, OMIM, Johns Hopkins University, March 14, 2007
[for Professionals mainly]
Sexual Ateleiotic Dwarfism;
Growth Hormone Deficiency, Isolated, Autosomal Recessive;
Type IA, Included;
Hastings Gilford (1904) called dwarfs with normal body proportions ateleiotic ('not arrived at perfection'). He distinguished sexual and asexual types and referred to patients with the former type as 'Tom Thumb dwarfs.' The 2 types correspond to what are referred to here as pituitary dwarfism I and III, respectively. The first type has an isolated deficiency of growth hormone, whereas the second has deficiency of all anterior pituitary hormones ...
Victor A. McKusick, OMIM, Johns Hopkins University, July 17, 2007
Gene Map Locus: 5p13-p12 ... Laron Type Dwarfism I;
Growth Hormone Receptor Deficiency;
Laron syndrome is characterized by clinical hyposomatotropism manifest by short stature, delayed bone age, and occasionally blue sclerae and hip degeneration ... In vitro fibroblasts from patients with Laron dwarfism respond normally to serum growth factors ... In an inbred population of Spanish extraction in the province of Loja in southern Ecuador, Rosenbloom et al. (1990) studied 20 patients (2 to 49 years of age) with the clinical features of Laron syndrome ... The height of the patients ranged from 6.7 to 10.0 standard deviation (SD) below the normal mean height for age in the United States ...
Victor A. McKusick, OMIM, Johns Hopkins University, November 3, 1999
Pituitary Dwarfism With Normal Immunoreactive Growth Hormone And Low Somatomedin;
Biodefective Growth Hormone;
Kowarski et al. (1978) studied 2 unrelated boys, aged 3 years, with growth retardation and delayed bone ages ... low levels of somatomedin. Unlike the result in patients with Laron dwarfism (262500), exogenous human growth hormone induced normal levels of somatomedin and a significant increase in growth rate ...
Last Updated: 2008/1/07