Sirenomelia: A new type, Showing VACTERL Association with thomas syndrome and a review of literature

Abstract

Sirenomelia or "mermaid syndrome" is a rare congenital anomaly known since antiquity. This congenital anomaly is defined as a polymalformative syndrome that associates major muscle and skeleton abnormalities (unique lower limbs) with visceral abnormalities (unilateral or bilateral renal agenesis, anomalies of the abdominal vascularisation). This phenotype, typical of sirenomelia syndrome, may be more or less severe. The pathogenic mechanisms of this syndrome are still debated and its etiology remains unknown. We report here a new type of sirenomelia that we observed in a fetus belonging to the collection of the Department of Anatomy of Reims, which led us to perform a comprehensive review of the literature on the subject: this type has never been reported and cannot be classified according to the Stocker and Heifetz classification. Moreover, this case also presents a VACTERL association with Thomas syndrome.

Sirenomelia: A Multi‐systemic Polytopic Field Defect with Ongoing Controversies

“…Caudal dysgenesis is hypothesized to arise from a primary deficiency of caudal mesoderm (Duhamel, ; Alles and Sulik, ). This theory is supported by many authors (e.g., Duesterhoeft et al, ; Charlier et al, ; Thottungal et al, ; Gerard et al, ; Seidahmed et al, ; Moosa et al, ; Das et al, ; Lhuaire et al, ; Kaygusuz et al, ). Dias and Walker () suggested that a teratogenic event occurred during gastrulation that interfered with the formation of the notochord, resulting in abnormally developed caudal structures and concomitant neural tube defects.…”

“…In the mid‐16th century, the first objective descriptions concerning sirenomelia appeared and were ascribed to Rocheus in 1542 and Palfyn in 1553 (Kampmeier, ). In the early 18th century, sirenomelia was called monopodia or sympodia (Lhuaire et al, ). In the mid‐19th century, Saint‐Hilaire () and Forster (1861) described cases of sirenomelia and named the three externally discernible variants of sirenomelia: (1) symèles or sympus dipus (presence of two feet), (2) uromèles or sympus monopus (presence of one foot) or (3) syrénomèle or sympus apus (no discernible foot).…”

“…However, the classifications can be considered nothing more than discrete groups of a sirenomelic spectrum (Orioli et al, ). Additionally, reports exist in which sirenomelic fetuses do not fit in the Stocker and Heifetz classification (Lhuaire et al, ). This was due to the presence of dysmorphological ossified structures in the lower limb that did not correlate with one of the seven types.…”

A rare association: Sirenomelia with adrenalomegaly in an infant of diabetic mother

“…This deformity is defined as a polymalformative syndrome that associates muscular, skeleton, and visceral abnormalities [4,5]. Sirenomelia is characterized by complete fusion of the lower limbs, commonly associated with renal agenesis, absent external genitalia and other gastrointestinal defects [6].…”

Sirenomelia type VI (sympus apus) in one of dizygotic twins at Chiang Mai University Hospital

“…Moreover, we found a bifid thumb, which is a related upper limb defect. Radial aplasia/hypoplasia, radial club hands, polydactyly, thumb agenesis, upper limb reduction, lobster claw hands, webbed limbs and joint contracture have been reported with sirenomelia, and these upper limb defects can be found in approximately 30% of patients 2 4 11. This case was of note, as it was of an in vitro fertilisation, dizygotic twin pregnancy with sirenomelia, of which limited studies have been reported 12–15…”