Etiological Heterogeneity in Sirenomelia

Abstract

Two babies with sirenomelia are described. Case 1, one of twins, showed the full sirenomelia sequence in conjunction with atelencephaly and cebocephaly. Case 2 had malformations consistent with a diagnosis of the VATER association. Review of the literature indicates that the basic defect in sirenomelia and the VATER association lies in the formation and differentiation of mesodermal tissue and that sirenomelia, the VATER association, and monozygotic twinning show a complex etiological interrelationship.

Craniorachischisis totalis and sirenomelia

“…Moreover, although 5.2-15% of the infants had aplastic, hypoplastic, or dysplastic kidneys, no patient showed other changes typical of sirenomelia such as complete absence of the ureters, urinary bladder, and urethra, or severe internal genital abnormalities. Central nervous system anomalies, such as atelencephaly and Arnold-Chiari malformation, may be present in about 5% of patients with sirenomelia [Stevenson et al, 1986;Young et al, 1986;Duncan and Shapiro, 19881. However, to the best of our knowledge, only 5 previous patients have been reported with both anencephaly and sirenomelia.…”

Severe brain and limb defects with possible autosomal recessive inheritance: A series of six cases and review of the literature

“…There has been a report of a patient with the XK aprosencephaly syndrome in a family where 2 sibs had neural tube defects [Townes et al, 1988]. A case of XK aprosencephaly with severe defects of the lower limbs was found in a fetus from a twin-pair [Young et al, 1986]. Along the same line, 2 fetuses conceived from a consanguineous couple had aprosencephaly and cerebellar dysgenesis [Florell et al, 1996].…”

Atelencephalic microcephaly: a case report and review of the literature

“…Eight of the 11 patients with aprosencephaly presented with a holoprosencephalic facies; the case of Lurie et al [12] lacked such facial abnormalities. Of the ten patients with atelencephaly only the patient of Young et al [27] had a holoprosencephalic facies. This patient also had a sirenomelia.…”