Mermaid syndrome: Rare genetic anomaly.

Mermaid syndrome (Sirenomelia) is a rare fatal congenital anomaly. The prevalence is reported to be 1 in 100,000 births. The baby appears to have a fish-like tail and joined legs featuring a mermaid at the time of birth or during antenatal screening. Most of these patients die shortly after birth, denoting rare survival rate. Gastrointestinal and genitourinary obstruction with single umbilical artery are the clinical symptoms. Two important hypotheses support the Sirenomelia disorder: the artery steal hypothesis, called the vitelline artery, and the blastogenesis defect hypothesis. There is no known reason for MS, but certain risk factors need to be identified, which include mother aged more than 40 years or less than 20 years at the time of giving birth, cousin marriage, exposure to teratogenic agents, and family history. A case of this rare congenital disorder was seen in Civil Hospital Faisalabad, Pakistan, which was referred from Duniyapur, District Lodhran, Pakistan. The neonate presented with fused lower limbs, congenital heart disease, and high-grade fever. The mother had a history of gestational diabetes mellitus and hypertension. The baby had fused legs, unidentified internal and external genital system, thumbs anomaly, bile in vomit, and despite life-saving efforts, the patient expired after five days of birth. There is lack of information regarding symptoms and a lack of prenatal screening for MS. Hence, there is a need to create awareness among health care professionals to identify the disease on screening for early diagnosis.

Sirenomelia: Review of a Rare Syndrome with Case Report, Review of Anatomy, and Thoughts on Management.

BACKGROUND: Sirenomelia is a rare syndrome in which the infant is born with the legs fused from the pelvis to the feet. Sirenomelia is often fatal in the neonatal period because of multiple other anomalies. The feet may be absent; if present, they are often splayed outward or face backward. There are no case reports of any patient with this syndrome who has been able to walk after separation of the legs. METHODS: The authors report on their patient with sirenomelia who was born with the feet facing backward but otherwise normal-appearing hips and thighs and no other anomalies that would lead to fatality in the near future. After preoperative tissue expansion, the authors performed separation of the legs with through-knee amputations, utilizing a vascularized flap from the lower part of the legs based on the sciatic vessels for coverage of the perineum. There was no need for skin grafts or dermal matrices and the patient was referred to physical therapy after recovery from surgery in an attempt to allow her to ambulate. RESULTS: The patient began to ambulate on her stumps early after surgical repair and is now walking with stubby prostheses. Her other medical issues have remained stable and nonproblematic. CONCLUSIONS: Selected patients with sirenomelia may be able to walk after separation of the legs, depending on the status of other congenital differences as well as the status of the legs when separated. Careful workup with multidisciplinary planning of overall care as well as surgical care is essential.

A rare case of radius hemimelia: a case report.

Radial dysplasia congenital defect resulting in shortening of the forearm due to congenital shortening of the radius. Isidore Geoffroy Saint-Hilaire coined the term "hemimelia" around 1836-1837. Affected individuals may also have reduced limb functions abnormalities of the soft tissues, vasculature of the forearm. The management consist of splinting, stretching, and centralization. Physical therapy management plays a vital role in regaining hand function and improving quality of life. In severe cases, surgical correction such as osteotomy. Radial hemimelia is a rare disorder with 1/5000-30,000 live birth. A 16-year-old girl was admitted to Acharya Vinoba Bhave Rural Hospital (AVBRH) with complaints of weakness of the right upper limb along with a tingling sensation from the past 1 year. She was operated on with ulnar osteotomy and physical therapy management was initiated which consists of regaining mobility and strength and making the patient functionally independent. We concluded that a well structure physical therapy protocol along with medical therapy post-surgery improved the overall status of the patient.

Sirenomelia with associated systemic anomalies - an autopsy report in a full term neonate.

The mermaid syndrome, also known as sirenomelia, is considered an extremely rare congenital developmental disorder characterized by anomalies of the lower spine and lower limbs. Affected babies are born with partial or total leg fusion. Sirenomelia is thought to affect one in every 60,000 to 100,000 infants. We report a case of sirenomelia occurring in a 28-year-old multiparous woman, a heavy smoker with gestational diabetes. In the other 5 pregnancies, however, she gave birth to normal babies. The post mortem examination completed the diagnosis, revealing also multiple malformations of several systems: respiratory, gastro-intestinal, genito-urinary and cardiovascular. In our full term neonate case with grade VI sirenomelia, the presence of a single umbilical artery plus the abdominal aorta with an aberrant trajectory that ends in the umbilical cord differentiates this condition from caudal regression syndrome and also explains the under-development of pelvic organs (secondary to vascular steal phenomena).

Common pathogenesis for sirenomelia, OEIS complex, limb-body wall defect, and other malformations of caudal structures.

Decades of clinical, pathological, and epidemiological study and the recent application of advanced microarray and gene sequencing technologies have led to an understanding of the causes and pathogenesis of most recognized patterns of malformation. Still, there remain a number of patterns of malformation whose pathogenesis has not been established. Six such patterns of malformation are sirenomelia, VACTERL association, OEIS complex, limb-body wall defect (LBWD), urorectal septum malformation (URSM) sequence, and MURCS association, all of which predominantly affect caudal structures. On the basis of the overlap of the component malformations, the co-occurrence in individual fetuses, and the findings on fetal examination, a common pathogenesis is proposed for these patterns of malformation. The presence of a single artery in the umbilical cord provides a visible clue to the pathogenesis of all cases of sirenomelia and 30%-50% of cases of VACTERL association, OEIS complex, URSM sequence, and LBWD. The single artery is formed by a coalescence of arteries that supply the yolk sac, arises from the descending aorta high in the abdominal cavity, and redirects blood flow from the developing caudal structures of the embryo to the placenta. This phenomenon during embryogenesis is termed vitelline vascular steal.

Dichorionic twin pregnancy with sirenomelia and chromosomal anomaly in 1 fetus: A case report.

RATIONALE: Sirenomelia is a rare congenital malformation that threatens fetal survivals. The cases in which twin with sirenomelia and chromosomal abnormality have been seldomly reported. We reported a dichorionic twin case in which one twin had sirenomelia, the other twin had a normal phenotype, and they had different chromosomal abnormalities. PATIENT CONCERNS: The abnormal twin was found at 22 weeks by ultrasound. The sirenomelia fetus was complicated with a thoracic stenosis, enlarged rectum without anal opening, the absence of bilateral kidneys, a single umbilical artery, a single lower limb, the abnormal curvature of spine, double outlet of right ventricle, which were the indicatives of the chromosome detection. DIAGNOSIS: The copy number variation of the sirenomelia fetus was detected as a deletion of 4.8Mb in 11p11.12-11q11. The co-twin was found with del(Y)(q11.223q11.23), which was as the same as his father's. The mother had normal chromosome. The parents had normal phenotypes. It was firstly reported a microdeletion with sirenomelia fetus. INTERVENTIONS: There was no specific treatments for the twins. OUTCOMES: Intrauterine death of the sirenomelia fetus was found at 27 weeks and postnatal death after inevitable abortion happened to the co-twin. LESSONS: Prenatal ultrasound was responsible for recognizing sirenomelia, and the detailed ultrasound scanning and chromosome detection should be done for the co-twin. The etiology of sirenomelia remains unclear, and genetic detection is also necessary for its pathogenesis research.

Sirenomelia associated with VACTERL and VACTERL-H syndrome / Sirenomelia asociaciada con síndrome de VACTERL y VACTERL-H

Sirenomelia or mermaid syndrome is an extremely rare congenital lethal malformation with a frequency between 1.5 and 4.2 per 1 000 000 pregnancies.The association of sirenomelia with the VACTERL association is very rare, with twenty cases reported in the literature and only two cases with VACTERL-H. We present two cases of sirenomelia, type I and type II associated with VACTERL-H and VACTERL syndromes and we review the literature. First time pregnancy women aged 15 and 40 years, without harmful habits and diseases, where between 25-27 gestational week (GW) the prenatal study identifies malformative fetus and the pregnancy is interrupted by medical evidence. The fetopathological examination in the first case identified sirenomelia type I associated with myelomeningocele, hydrocephalus, anal imperforation, single umbilical artery, bilateral renal agenesis, ureteral and bladder agenesis, tracheo-esophageal fistule, agenesis of external genitals, monkey fold of the left palm of the hand - VACTERL-H. In the second case, where genetic testing is normal, sirenomelia type II associated with agenesis of external genitalia, anal imperforation, myelomeningocele, dolichocrania, macroglossia, low set ears, left preauricular skin tag, long philtrum, lung hypoplasia, split cadiac apex, single umbilicalis artery, blind end colon, hepatomegaly, accessory spleen, polycystic horseshoe kidney, uterine and vaginal agenesis, presence of two ovaries and duodenal stenosis - VACTERL association. This two cases, lead us to believe that sirenomelia and the VACTERL association are probably different manifestations of a pathogenetic process leading to disorders of blastogenesis at different levels during embryonic development.

La sirenomelia es una malformación congénita y excepcionalmente rara, con una frecuencia entre 1,5 y 4,2 en un millón de embarazos. La combinación de la sirenomelia con el síndrome de VACTERL es igualmente rara. La literatura especializada informa sobre la existencia de una veintena de casos solamente; en lo que respecta a su asociación con el síndrome de VACTERL-H se conocen solo dos casos. Luego de realizar una revisión de la literatura presentamos dos casos de sirenomelia asociada con los síndromes de VACTERL-H y de VACTERL En el estudio se analizaron los primeros embarazos de dos mujeres, edad de 15 y de 40 años, respectivamente, ambas mujeres completamente sanas y sin hábitos viciosos. Entre la vigésima quinta y la vigésima séptima semana gestacional (SG) del embarazo ambas mujeres, el análisis prenatal comprueba la existencia de malformación del feto debido a lo cual los embarazos fueron interrumpidos por prescripción médica. El análisis fetopatológico del primer caso comprueba la existencia de sirenomelia de tipo I asociada con mielomeningocele, hidrocefalia, atresia anal, arteria umbilical única, agenesia bilateral de los riñones y de los ureteres que transportan la orina desde los riñones hasta la vejiga, fístula traqueoesofágica, agenesia de los órganos genitales externos, línea simiesca en la palma de la mano izquierda - VACTERLH. En el segundo caso, en que el análisis genético ha resultado normal, se observó la presencia de sirenomelia de tipo II asociada con agenesia de los órganos genitales externos, atresia anal, mielomeningocele, dolicocrania, macroglosia, orejas bajas, filtrum alargado, hipoplasia pulmonar, ápice cardíaco escindido, arteria umbilical única, colon terminado en ciego, bazo accesorio, poliquistosis renal, riñón en herradura, agenesia vaginal y de útero, presencia de dos ovarios y estenosis duodenal - VACTERL asociación. Los dos casos investigados permiten llegar a la conclusión de que la sirenomelia y su combinación con el síndrome de VACTERL probablemente sean manifestaciones diferentes de un proceso patogenético que conlleva la alteración de la blastogénesis en distintos niveles durante el proceso del desarrollo embrionario.

Upper limb phocomelia: A prenatal case of thrombocytopenia-absent radius (TAR) syndrome illustrating the importance of chromosomal microarray in limb reduction defects.

OBJECTIVE: To describe the ultrasonographic, pathologic and molecular findings in a fetus with TAR syndrome, and to illustrate the contribution of chromosomal microarray analysis (CMA) to the etiological investigation of fetal upper limb reduction defects. CASE REPORT: A 35-year-old woman was referred for Genetic Counseling after pregnancy termination for severe upper limb bilateral phocomelia detected in the second trimester. Fetal autopsy showed severe shortening of the arms and forearms. The fetal skeletal survey confirmed the absence of the radii, ulnae and humeri. CMA revealed an interstitial deletion in 1q21 including the RBM8A gene. Subsequent Sanger sequencing of this gene identified a hypomorphic mutant allele, c.-21G > A, confirming the diagnosis of TAR syndrome. CONCLUSION: The differential diagnosis of upper limb defects is broad. Identification of their cause is essential for adequate genetic counseling including prognosis and recurrence risk estimation. CMA should be considered in fetuses with upper limb reduction defects, especially when the thumbs are present.

Exome sequencing identifies the first genetic determinants of sirenomelia in humans.

Sirenomelia is a rare severe malformation sequence of unknown cause characterized by fused legs and severe visceral abnormalities. We present a series of nine families including two rare familial aggregations of sirenomelia investigated by a trio-based exome sequencing strategy. This approach identified CDX2 variants in the two familial aggregations, both fitting an autosomal dominant pattern of inheritance with variable expressivity. CDX2 is a major regulator of caudal development in vertebrate and mouse heterozygotes are a previously described model of sirenomelia. Remarkably, the p.(Arg237His) variant has already been reported in a patient with persistent cloaca. Analysis of the sporadic cases revealed six additional candidate variants including a de novo frameshift variant in the genetically constrained NKD1 gene, encoding a known interactor of CDX2. We provide the first insights for a genetic contribution in human sirenomelia and highlight the role of Cdx and Wnt signaling pathways in the development of this disorder.

Sirenomelia associated with an anterior abdominal wall defect: a case report.

BACKGROUND: Sirenomelia is a rare and fatal congenital defect. The rarity of this case and its association with abdominal total wall defect drove us to report this case. CASE PRESENTATION: We report a rare case of sirenomelia characterized by lower limb fusion, thoracolumbar spinal anomalies, sacrococcygeal agenesis with a rudimentary tail, and genitourinary and anorectal atresia. Coexistent anterior abdominal wall defect in this case highlights its fatalness because of complications associated with the malformation. CONCLUSIONS: Sirenomelia syndrome has seldom been reported. The present case highlights the rare atypical association of sirenomelia with anterior abdominal wall defect. Because the investigations were done in a low-resource setting, the etiology regarding this case remains unclear.

Optimizing the use of fibula in type II tibial hemimelia: early results.

We describe a technique for optimal use of fibula in reconstruction of type II tibial hemimelia. Six affected children with mean age of 1.4 years and treated over a 5-year period were reviewed. All underwent staged reconstruction by lowering the fibula to below knee level using Ilizarov soft tissue distraction, transfer of distal fibula under proximal tibia, and foot centralization. Mean follow-up period was 3.6 years (range: 1.6-6.05 years). Mean age at follow-up was 4.4 years, and increase in length was 4.08 cm. Tibiofibular union and foot centralization were universally achieved. Mild residual equinovarus deformity was present in three children and braced. Our technique allowed significant length gain and foot centralization in toddlers without distraction osteogenesis.

Femoral bifurcation and bilateral tibial hemimelia: case report.

Femoral bifurcation and tibial hemimelia are rare anomalies described as a variant of Gollop-Wolfgang complex. This article presents a case of Gollop-Wolfgang complex without hand ectrodactyly. A 5-year old patient presented with bilateral tibial hemimelia and left femoral bifurcation. The patient's left limb lacked knee extensor mechanism, disarticulation was done. The right leg which had Jones type 2 tibia hemimelia was treated with tibiofibular synostosis. Currently patient is ambulant with prosthesis on the left limb and ankle foot orthosis on the right. In the absence of proximal tibial anlage, especially in patients with femoral bifurcation, the knee should be disarticulated. Tibiofibular synostosis is a good choice in the presence of a proximal tibial anlage with good quadriceps function.

A Novel Frameshift Mutation in ESCO2 Gene in Roberts Syndrome.

Roberts syndrome is a very rare autosomal recessive inheritance pattern genetic disorder characterised by symmetric bilateral extremity deformities, midfacial defect, and severe intellectual deficit. These patients also grow slowly prenatal and postnatal. RBS is caused by mutation in the ESCO2 gene. With these clinical and radiological findings, the case was diagnosed as Roberts syndrome. Full gene sequencing of the ESCO2 gene for the patient was done. In this patient, a novel frameshift mutation was identified in the ESCO2 gene.

Sirenomelia: A Case Report.

Sirenomelia is primarily a congenital anomaly where a normally paired lower limb is replaced by a single midline limb and is characterized by single umbilical artery. Such cases though considered rare do occur at our set-up and to make health workers aware regarding the condition, so that they can be managed well when encountered, lays the importance of reporting such case. A referred case of Sirenomelia from Dhading district hospital was presented to Emergency department of Paropakar Maternity and Women's Hospital on 6th March 2016 of 18 year "Young Primigravida at 34 week and 5 days of gestation in second stage of labor" following ultrasonography diagnosis for better management. After confirming the diagnosis, preterm vaginal delivery was performed with a live baby of 1250 gm consisting of multiple congenital anomalies and poor Apgar score. Such cases do occur at our set-up so that if anomaly scanning is done routinely, they could be picked up early and management becomes easier. Keywords: case report; ectromelia; fused legs and feet; Mermaid syndrome; Sirenomelia.

A rare case of tibial hemimelia, surgical technique and clinical results.

We report a nine-year-old boy with a type IIIa tibial hemimelia, according to the new Paley classification. We describe the x-ray findings, the surgical treatment technique, and the prognostic course of the patient. Descriptions of such cases are very infrequent in the literature and type of treatment is still object of debate.

Prenatal diagnosis of a 1.6-Mb 4p16.3 interstitial microdeletion encompassing FGFRL1 and TACC3 associated with bilateral cleft lip and palate of Wolf-Hirschhorn syndrome facial dysmorphism and short long bones.

OBJECTIVE: We present prenatal diagnosis of a 4p16.3 interstitial microdeletion associated with bilateral cleft lip and palate and short long bones on prenatal ultrasound, and we discuss the genotype-phenotype correlation. MATERIALS AND METHODS: A 32-year-old woman underwent amniocentesis at 22 weeks of gestation because of bilateral cleft lip and palate and short limbs on prenatal ultrasound. Conventional cytogenetic analysis was performed on cultured amniocytes and parental bloods. Oligonucleotide array comparative genomic hybridization (aCGH) was performed on the DNAs extracted from uncultured amniocytes, parental bloods and umbilical cord. Metaphase fluorescence in situ hybridization (FISH) was performed on cultured amniocytes. RESULTS: Amniocentesis revealed a karyotype of 46,XY. The parental karyotypes were normal. aCGH analysis on uncultured amniocytes revealed a 1.66-Mb interstitial microdeletion at 4p16.3 encompassing 23 Online Mendelian Inheritance of in Man (OMIM) genes including FGFRL1 and TACC3. The parents did not have such a deletion. The pregnancy was subsequently terminated, and a malformed fetus was delivered with typical Wolf-Hirschhorn syndrome (WHS) facial appearance and bilateral cleft lip and palate. aCGH analysis of the umbilical cord confirmed the prenatal diagnosis with a result of arr 4p16.3 (72,447-1,742,649) × 1.0 [GRCh37 (hg19)]. Metaphase FISH analysis of cultured amniocytes confirmed a 4p16.3 microdeletion. CONCLUSION: Haploinsufficiency of FGFRL1 and TACC3 at 4p16.3 can be associated with bilateral cleft lip and palate of WHS facial dysmorphism and short long bones. Prenatal diagnosis of facial cleft with short long bones should raise a suspicion of chromosome microdeletion syndromes.

Al-Awadi-Raas-Rothschild syndrome with dental anomalies and a novel WNT7A mutation.

Al-Awadi-Raas-Rothschild syndrome (AARRS; OMIM 276820) is a very rare autosomal recessive limb malformation syndrome caused by WNT7A mutations. AARRS is characterized by various degrees of limb aplasia and hypoplasia. Normal intelligence and malformations of urogenital system are frequent findings. Complete loss of WNT7A function has been shown to cause AARRS, however, its partial loss leads to the milder malformation, Fuhrmann syndrome. An Indian boy affected with AARRS is reported. A novel homozygous base substitution mutation c.550A > C (p.Asn184Asp) is identified in the patient. Parents were heterozygous for the mutation. In addition to the typical features of AARRS, the patient had agenesis of the mandibular left deciduous lateral incisor. The heterozygous parents had microdontia of the maxillary left permanent third molar and taurodontism (enlarged dental pulp chamber at the expense of root) in a number of their permanent molars. Whole exome sequencing of the patient and his parents ruled out mutations in 11 known hypodontia-associated genes including WNT10A, MSX1, EDA, EDAR, EDARADD, PAX9, AXIN2, GREM2, NEMO, KRT17, and TFAP2B. In situ hybridization during tooth development showed Wnt7a expression in wild-type tooth epithelium at E14.5. All lines of evidence suggest that WNT7A has important role in tooth development and its mutation may lead to tooth agenesis, microdontia, and taurodontism. Oral examination of patients with AARRS and Fuhrmann syndromes is highly recommended.

Upper limb hemimelia in a twin pregnancy which was obtained by an ICSI and PGD in a woman with mosaic Turner's syndrome and the prognosis.

Turner's syndrome (TS) is depicted as a total or partial absence of X chromosome, and occurs in approximately 1/2200 of live born females. Generally, mosaic patients are diagnosed following karyotype analysis due to recurrent pregnancy loss, repeated in vitro fertilization (IVF) failure, and a history of malformed babies. The purpose of this case report is to show that even a selection of normal karyotype embryos can result in abnormalities for those with mosaic TS. A 32-year old patient who underwent IVF after ICSI-PGD, and was diagnosed with 45X/46XX karyotype. At the 12-week scan, one of the fetuses had an upper limb hemimelia in one arm, and feticide was applied to that fetus. The patient delivered a healthy, 2980 g female baby at the thirty-eighth week. In mosaic TS pregnancies (even those obtained by ICSI-PGD), fetal anomaly risk is high. Therefore, careful prenatal scanning is needed for these pregnancies.