Caudal dysgenesis, sirenomelia, and situs inversus totalis: a primitive defect in blastogenesis.
Caudal dysgenesis (CD) constitutes a heterogeneous spectrum of congenital caudal anomalies, including varying degrees of agenesis of the vertebral column, as well as anorectal and genitourinary anomalies. Sirenomelia, characterized by a fusion of the lower limbs, could represent the most severe end of this spectrum. The two main debated pathogenic hypotheses are an aberrant vascular supply versus a primary axial mesoderm defect. We present the autopsy findings of two fetuses of non-diabetic mothers, with normal karyotype. Both fetuses presented situs inversus associated with a CD, in one case consisting of sirenomelia, establishing a very rare association profile that might be random. This association also suggests the occurrence of a common pathogenic mechanism, in accordance to recent genetic data, such as displayed in the Kif3A murine mutation phenotype. Some cases of sirenomelia and CD could represent developmental field defects of blastogenesis involving the caudal mesoderm, rather than being related to vascular insufficiency.
Rougemont
Anne-Laure
AL
Department of Pathology, CHU Sainte-Justine, Montreal, Quebec, Canada.
Bouron-Dal Soglio
Dorothée
D
Désilets
Valérie
V
Jovanovic
Mubina
M
Perreault
Gilles
G
Laurier Oligny
Luc
L
Fournet
Jean-Christophe
JC
D037881:Aborted Fetus / Q000002:abnormalities*; D004480:Ectromelia / Q000196:embryology*; D047109:Fetal Development; D006801:Humans; D012857:Situs Inversus / Q000196:embryology*; D013131:Spine / Q000002:abnormalities; D016216:Ultrasonography, Prenatal; D014564:Urogenital Abnormalities / Q000196:embryology