Sirenomelia- a mermaid like condition-.pptx

A mermaid like condition in newborns.

1. Sirenomelia “The Mermaid Syndrome” By Dr Shadia Aborakhes 1

2. The Mermaid Syndrome: It is a rare congenital anomaly characterized by partial or complete fusion of lower limbs and is associated with other anomalies. Male female ratio 2.7:1 Incidence is 1 in 60,000 to 100,000 births. More frequently accurs in monozygotic twins than dizygotic twins. It has been classified into 7 classes by the presence or absence of bones within the lower limbs. 2

3. The 7 types: 3

4. Clinical finding: .Complete or partial fusion of lower legs. Affected infants may have one or two femurs within one leg. They may have one foot, both feet which may be rotated outward. .Coccyx is usually absent and so is sacrum it may be partially or completely absent. 4

5. Clinical findings continued.. Bilateral complete or partial renal agenesis. Absent or ambiguous external genetalia . Single umblical artery is also common and a diagnostic clue. Cleft palate pulmonary hypoplasia might be also present. Neural tube defects. Esophegeal atresia Omphalocele Intestinal malrotation Hypoplastic left heart syndrome . Potter’s syndrome 5

6. Etiologies Both enviromental and genetic factors are involved. Infants have normal karyotypes . Mothers younger thsn 20 and older than 40 have greater incidence. Maternal exposure during gestation to teratogenic factors such as cocaine ,pollution , tobacco ,cigarettes and radiation are risk factors. GDM has also been associated with sirenomelia . 6

7. P athogenesis Two hypothesis have been proposed: 1.Vitelline Artery Steal hypothesis: This theory suggests that there is a shunting of blood via an abnormal abdominal artery from higher part of aorta towards the placenta. This leaves caudal part of the embryo poorly profused . Hence, resulting in partial or complete agenesis in caudal structures. 2. Defective Blastogenesis hypothesis: An impaired blastogenesis occurs, in which lower body organs have inappropriate angiogenesis leading to insufficient growth and incomplete development of the caudal region. 7

8. Antenatal diagnosis Sirenomelia can be diagnosed as early as 14 weeks of gestation with the following symptoms: 1.Nuchal translucency and renal agenesis 2.Fused/single lower limb. 3.Single umblical artery. 4.Oligohydraminous (yet this makes the diagnosis hader ) 8

9. Us US feature of sirenomelia 9 The mother decides to abort the fetus after confirming the condition with an X-ray

10. Prognosis The condition is usually fetal. Many of these pregnancies end in spontanous miscarriages. Half of the cases are stillborn. Few manage to live the early neonatal period. 10

11. Picture an infant with mermaid syndrome 11

12. References: Google scholar Google images An article: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6235678 / 12