Caudal Dysplasia Syndrome and Sirenomelia: Are They Part of a Spectrum?

Abstract

Caudal dysplasia syndrome (CDS) is associated with hypoplastic lower extremities, caudal vertebrae, sacrum, neural tube, and urogenital organs. Sirenomelia is characterized by a single lower extremity, absent sacrum, urogenital anomalies, and imperforate anus. There is controversy in the medical literature about whether sirenomelia and CDS are part of the spectrum of the same malformation. Patients with CDS and sirenomelia were identified from our pathology files from 1991 to 2006. Maternal history, pathologic examination, and radiographs were collected and tabulated. We found 9 cases with CDS and 6 with sirenomelia. Fully 7 of 9 patients with CDS (77.7%) versus none of sirenomelic babies were infants of diabetic mothers. Congenital heart disease was present in 5 patients with CDS (55.5%) and none of the infants with sirenomelia. Of 9 children with CDS 2 (22.2%) had bilateral renal agenesis versus 66% of sirenomelics. Single umbilical artery was found in 33% of cases with CDS and 100% of children with sirenomelia. External genitalia were ambiguous in 2 of 9 patients (22.2%) with CDS and in all patients with sirenomelia. Imperforate anus was found in 10 cases (66.6%) divided as 4 of 9 babies with CDS (44.4%) and all patients with sirenomelia. Three patients with CDS had concomitant maternal diabetes mellitus and chronic hypertension. These babies also had cleft lip and palate. Congenital heart disease was found in 55.5% of cases with CDS and none of the children with sirenomelia. We conclude that although CDS and sirenomelia share many similar features, they are two different entities.

A Fetus with Hemifacial Microsomia and Sirenomelia. The Same Mesodermal Defect Spectrum?

“…VACTERL, CD, and sirenomelia result from the pleiotropic effect of a single agent simultaneously affecting a variety of midline structures [10]. Debate still exists as to whether CD and sirenomelia are separate entities [9] or whether they represent part of the same pathologic spectrum. Recent studies based on clinical findings support the original theory of a caudal regression-sirenomelia spectrum [3] and propose that same insults at different timings of embryonic development may be the cause of the diverse clinical findings [11].…”

“…Similar defects are seen in axial mesodermal dysplasia, VACTERL (Vertebral anomalies, Anal atresia, Cardiac malformations, Tracheoesophageal fistula, Renal anomalies, Limb anomalies) association, and caudal dysgenesis (CD). Recent studies consider sirenomelia as the most severe form of CD or VACTERL although others still support the idea that sirenomelia is a different pathologic entity [3,[7][8][9][10][11].…”

Mermaid syndrome

“…Kaudal disgenezinin bir tipi mi yoksa tamamen ayri bir durum mu oldugu halen tarti §ma konusudur (3,6,(9)(10)(11)(12)(13). Patojenezi tam olarak açiklanamamakia birlikte bazi teoriler ileri sürülmü §tür.…”

“…Olgumuzda bacaklar sadece deri ile birle §mi §ti. Bacaklarin yapi §ikligi yaninda en sik bildirilen bulgular göbek kordonunda tek arter bulunmasi ve böbrek geli §im bozuklugudur (1,12,13). Bizim olgumuzda da göbek kordonunda tek arter vardi ve böbrekler, idrar torbasi, üreterler yoktu.…”

“…Denizkizi sendromunda genellikle di § ve iç cinsiyet organlari tam olarak geli §mez (3,(9)(10)(11)(12)14). Bizim olgumuzda penis görünümlü bir yapi bulunmakia birlikte, skrotum geli §memi §ti ve testisler ele gelmiyordu.…”