Genetic Mutations, Birth Lengths, Weights and Head Circumferences of Children with IGF-I Receptor Defects. Comparison with other Congenital Defects in the GH/IGF-I axis
PEDIATRIC ENDOCRINOLOGY REVIEWS PER
Authors: Essakow, Jenna Lee; Lauterpacht, Aharon; Lilos, Pearl; Kauli, Rivka; Laron, Zvi
Background In recent years more and more genetic defects along the GHRH-GH-IGF-I axis have been reported. Mutations of the IGF-1 receptor (R) are a rare abnormality of whom only the heterozygote progenies survive. Objective To summarize, from the literature, data on birth length, weight and head circumference of neonates with IGF-I-R mutations, and to correlate the data with that of other types of mutations in the GH/IGF-I axis. Subjects Sixty seven neonates from 24 published articles were included and forty seven different mutations of the IGF-I (R) located on chromosome 15 have been identified. Results Mean (+/- SD) birth length (BL), available for 26, (10 M, 16F) neonates with a gestational age of 34-41weeks, was 44.2 +/- 4cm; one was premature (30cm at 31 weeks). There was a significant correlation between birth length and gestational age (GA) r=0.71 (p<0.001). Mean birth weight (BW) of 41 neonates (18M, 23F) was 2388 +/- 743gr. Two premature neonates weighed 650gr and 950gr respectively. The BW correlated significantly with gestational age, (males: r=0.68; p=0.007, females: r=0.49; p=0.024). The BMI of 25 neonates ranged from 6 to 13. In 22 records marked microcephaly was ascertained or stated. Nine of 16 mothers were short (133 - 148cm), m +/- SD = 150.5 +/- 7.3cm.
The immunoglobulin heavy chain locus in the platypus (Ornithorhynchus anatinus)
Authors: Gambon-Deza, F.; Sanchez-Espinel, C.; Magadan-Mompo, S.
Immunoglobulins loci in mammals are well known to be organized within a translocon, however their origin remains unresolved. Four of the five classes of immunoglobulins described in humans and rodents (immunoglobulins M, G, E and A-IgM, IgG, IgE and IgA) were found in marsupials and monotremes (immunoglobulin D-IgD was not found) thus showing that the genomic structure of antibodies in mammals has remained constant since its origin. We have recently described the genomic organization of the immunoglobulin heavy chain locus in reptiles (IGHM, IGHD and IGHY). These data and the characterization of the IGH locus in platypus (Ornithorhynchus anatinus), allow us to elucidate the changes that took place in this genomic region during evolution from reptile to mammal. Thus, by using available genome data, we were able to detect that platypus IGH locus contains reptilian and mammalian genes. Besides having an IGHD that is very similar to the one in reptiles and an IGHY, they also present the mammal specific antibody genes IGHG and IGHE, in addition to IGHA. We also detected a pseudogene that originated by recombination between the IGHD and the IGHM (similar to the IGHD2 found in Eublepharis macularius). The analysis of the IGH locus in platypus shows that IGHY was duplicated, firstly by evolving into IGHE and then into IGHG. The IGHA of the platypus has a complex origin, and probably arose by a process of recombination between the IGHM and the IGHY. We detected about 44 VH genes (25 were already described), most of which comprise a single group. When we compared these VH genes with those described in Anolis carolinensis, we find that there is an evolutionary relationship between the VH genes of platypus and the reptilian Group III genes. These results suggest that a fast VH turnover took place in platypus and this gave rise to a family with a high VH gene number and the disappearance of the earlier VH families. (C) 2009 Elsevier Ltd. All rights reserved.