Abnormal urethra formation in mouse models of split-hand/split-foot malformation type 1 and type 4

Eur J Hum Genet. 2008 Jan;16(1):36-44. doi: 10.1038/sj.ejhg.5201925. Epub 2007 Sep 19.

Abstract

Urogenital birth defects are one of the common phenotypes observed in hereditary human disorders. In particular, limb malformations are often associated with urogenital developmental abnormalities, as the case for Hand-foot-genital syndrome displaying similar hypoplasia/agenesis of limbs and external genitalia. Split-hand/split-foot malformation (SHFM) is a syndromic limb disorder affecting the central rays of the autopod with median clefts of the hands and feet, missing central fingers and often fusion of the remaining ones. SHFM type 1 (SHFM1) is linked to genomic deletions or rearrangements, which includes the distal-less-related homeogenes DLX5 and DLX6 as well as DSS1. SHFM type 4 (SHFM4) is associated with mutations in p63, which encodes a p53-related transcription factor. To understand that SHFM is associated with urogenital birth defects, we performed gene expression analysis and gene knockout mouse model analyses. We show here that Dlx5, Dlx6, p63 and Bmp7, one of the p63 downstream candidate genes, are all expressed in the developing urethral plate (UP) and that targeted inactivation of these genes in the mouse results in UP defects leading to abnormal urethra formation. These results suggested that different set of transcription factors and growth factor genes play similar developmental functions during embryonic urethra formation. Human SHFM syndromes display multiple phenotypes with variations in addition to split hand foot limb phenotype. These results suggest that different genes associated with human SHFM could also be involved in the aetiogenesis of hypospadias pointing toward a common molecular origin of these congenital malformations.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Bone Morphogenetic Protein 7
  • Bone Morphogenetic Proteins / deficiency
  • Bone Morphogenetic Proteins / genetics
  • Disease Models, Animal
  • Foot Deformities, Congenital / embryology
  • Foot Deformities, Congenital / genetics
  • Gene Expression Regulation, Developmental
  • Genitalia / embryology
  • Hand Deformities, Congenital / embryology
  • Hand Deformities, Congenital / genetics
  • Homeodomain Proteins / genetics
  • Humans
  • Limb Deformities, Congenital / classification
  • Limb Deformities, Congenital / embryology
  • Limb Deformities, Congenital / genetics*
  • Mice
  • Mice, Knockout
  • Phosphoproteins / deficiency
  • Phosphoproteins / genetics
  • Syndrome
  • Trans-Activators / deficiency
  • Trans-Activators / genetics
  • Transforming Growth Factor beta / deficiency
  • Transforming Growth Factor beta / genetics
  • Urethra / abnormalities*
  • Urethra / embryology

Substances

  • BMP7 protein, human
  • Bone Morphogenetic Protein 7
  • Bone Morphogenetic Proteins
  • Dlx5 protein, mouse
  • Dlx6 protein, mouse
  • Homeodomain Proteins
  • Phosphoproteins
  • Trans-Activators
  • Transforming Growth Factor beta
  • Trp63 protein, mouse