International Journal of Health Sciences and Research www.ijhsr.org ISSN: 2249-9571

Case Report

Sirenomelia Sequence (Mermaid Syndrome) - A Rare Case

Nanda Patil, Parnika Garg*

Department of Pathology, Krishna Institute Of Medical Sciences, Karad, Maharashtra-415110

*Correspondence Email: [email protected]

Received: 06/03//2013 Revised: 30/03/2013 Accepted: 08/04/2013

ABSTRACT

Sirenomelia is a rare, congenital sporadic defect which occurs in newborn infants, more commonly seen in males. It is an extreme form of caudal regression, with extensive damage in the caudal portion of body resulting from an insult occurring before the twenty first day of gestation. Its most remarkable feature is external rotation with fusion of lower extremities. The other defects of caudal axis include imperforated anus, lower vertebral defects and genitourinary anomalies associated with cardiovascular, respiratory and upper malformations in 20-30% of cases. Renal agenesis or cystic renal dysplasia occurs in virtually all cases leading to & . We present a rare case of sirenomelia in a 20weeks abortus received for autopsy where almost all classical features of this defect were seen like fusion of the lower limbs,bilateral renal agenesis with Potter‟s facies, absent ,imperforated anus,malrotation and atresia of gut,narrow thorax with pulmonary hypoplasia. Key words: Sirenomelia, Caudal regression, Potter sequence

INTRODUCTION gastrointestinal, genitourinary, Sirenomelia also known as the cardiovascular and musculoskeletal systems. “mermaid syndrome” as it resembles the secondary to severe renal mystical mermaid. The term „„sirenomelia‟‟ dysplasia is universal. [3, 4] was derived from the sirens of Greek and Roman mythology. [1] It is a rare and fatal CASE REPORT congenital anomaly with an incidence of 0.8 A 20 year old primigravida with 5 to 1 case per 1,00,000 births. Male to months amenorrhea was registered for her Female ratio is 3:1. [2] The time of insult antenatal check up in our institute. Her resulting in the malformations is known to routine investigations were within normal occur between 28 to 32 days of gestation but limits. On further investigations her pre- the exact pathogenesis remains elusive, with natal ultrasound (USG) showed congenital some studies implicating caudal regression anomalies of foetus which were not or vascular steal phenomenon. [1, 3] The compatible with life. There was no evidence malformation sequence is composed of of mellitus, drug abuse or varying degrees of lower limb fusion along consanguineous marriage. The patient with multiple malformations of the underwent therapeutic abortion and fetus

International Journal of Health Sciences & Research (www.ijhsr.org) 127 Vol.3; Issue: 4; April 2013 was sent for autopsy. On autopsy lungs (figure 5) and blind loop intestine examination external examination of the (figure 6). Postmortem total body foetus showed fusion of lower limbs anteroposterior & lateral radiographs resulting in single fused lower limb with a demonstrated hemivertebrae with short thigh & a short leg having a kyphoscoliosis, absent sacrum, single rudimentary foot. There was kyphoscoliosis rudimentary with absent tibia & fibula (Figure 1), absent genitalia (Figure 2), flat &rudimentary tarsal bones (Figure 7). facial profile i.e Potter‟s facies (Figure 3) Considering these malformations of with high arched palate, imperforate anus lower limb & visceral abnormalities (Figure 4). On internal examination there diagnosis of sirenomelia (STOCKER TYPE was bilateral renal agenesis, absent urinary VII LEG DEFORMITY) was made. bladder, absent & ureter, hypoplastic

Fig 1 : Kyphoscoliosis Fig 2 : Absent Genitalia

Fig 3 : Potter‟s Facies Fig 4 : Imperforated Anus

International Journal of Health Sciences & Research (www.ijhsr.org) 128 Vol.3; Issue: 4; April 2013

Fig 5 : Hypoplastic Lung Fig 6 : Blind Loop Intestine

less than 20 years and older than 40 years. [1] Sirenomelia shows a great variability in the spectrum of the malformations. It was Stocker and Heifetz (1987) who classified the leg abnormalities into Types I to VII depending on the presence or absence of bones Type I being the least severe with presence of all bones as compared to the most severe Type VII which consists of a lower extremity with a fused femur and absence of both tibia and fibula. [3, 7] Another way of classifying sirenomelia is according to the number of lower bones present into three different types i.e A) Fig 7: Postmortem Radiogram: Hemivertebrae, Kypho- scoliosis, Single Femur, Absent Tibia, Fibula & Sacrum Sirenomelia apus: No feet only one tibia and one femur. B) Sirenomelia unipus : One DISCUSSION foot, two two tibia, and two fibula. Rocheus and Polfyr in the sixteenth C) Sirenomelia dipus: Two feet and two century gave the first description of fused legs giving the appearance of a flipper. sirenomelia but it was Duhamel who in 1961 [2] There are various theories about the defined the various anomalies associated etiology of the mermaid syndrome. Two with mermaid syndrome and labelled it as major theories are currently speculated. [1] the most severe form of caudal regression Duhamel explained the caudal regression syndrome. The etiology of this syndrome is syndrome to explain various congenital still unclear and a strong association with anomalies with sirenomelia being the most maternal diabetes and drug abuse has been severe form. He explained the observed. [2, 5] No chromosomal anomalies malformations as a result of defect in have been detected. [3, 6] It is three times blastogenesis and disturbances in the caudal more common in males with a higher mesodermal axis of the embryo prior to 4th incidence in identical twins. The risk of its week of gestation.[5] Stevenson 1986 occurrence depends on the maternal age of proposed an alternate theory of vascular

International Journal of Health Sciences & Research (www.ijhsr.org) 129 Vol.3; Issue: 4; April 2013 steal which is currently the most acceptable Journal of perinatology 2004;24:329- theory for the mermaid syndrome. He 331. postulated that blood is diverted from the 2. Reddy KR, Srinivas S, Kumar S, caudal region of the embryo to the placenta Reddys, Hariprasad, Irfan G M. due to shunting via an abnormal abdominal Sirenomelia a rare presentation. J artery, which gives rise to a nutritional Neonat Surg 2012(1):7-9. deprivation and abnormal development of 3. Morfaw F L, Nana PN. Sirenomelia the caudal structures. The site at which the in a cameroonian woman: a case purposed steal occurs determines the report and review of the severity of the anomalies. The mechanism of literature[v2;ref status:Indexed, this variation is not fully understood. [3] Both http://f1000r.es/OIDGLR]. F1000 of these theories appear to be Research 1:6. oversimplifications of the true etiology of 4. Kulkarni M.L, Sureshkumar C, sirenomelia as neither of them explains the Sindhur P.S. Sirenomelia with non-caudal anomalies, which have been spinabifida. Indian Pediatr. observes now and then. 1994;31:51-55. 5. Goodlow O. G,Sibley R J, Allen B CONCLUSION G, Kamanda W S,Gurlatte A C, Sirenomelia is a severe form of Rayfield W C. Sirenomelia:Mermaid caudal regression, the etiology of which is syndrome. Journal of the National still unclear. As this malformation is Medical Association 1988; 80(3): uniformly fatal, early antenatal diagnosis 343-346. with ultrasonography justifies therapeutic 6. Gouri M S, Kumari K M, Rao S termination of pregnancy. Severe G, Uma Devi Sirenomelia. Indian J oligohydraminos may limit the evaluation Pathol and Microbiol. 2009; resulting in fetal . In such 52(4):579-80. circumstances autopsy study helps to 7. Allepeuz C G, Haro E, Lamuño D G diagnose this syndrome. , Frías ML, Bertocchini F, ROS M. A clinical and experimental REFERENCES overview of sirenomelia: insight into 1. Browne M, Fitchev P, Adley B, the mechanisms of congenital limb Crawfords. Sirenomelia with an malformations. Diseases Models & Angiomatous Lumbosacral Myelo- Mechanisms. 2011;4:289-99. cystocele in a full term infant.

How to cite this article: Patil N, Garg P. Sirenomelia sequence (mermaid syndrome) - a rare case. Int J Health Sci Res. 2013;3(4):127-130.

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International Journal of Health Sciences & Research (www.ijhsr.org) 130 Vol.3; Issue: 4; April 2013