|Year : 2017 | Volume
| Issue : 2 | Page : 103-105
As rare as Hen's teeth: Tetra-amelia syndrome
Sheetal Gupta, RK Soni, Vishnu Agrawal, Prateek Agrawal, Pradeep Garg
Department of Pediatrics, S. P. Medical College, Bikaner, Rajasthan, India
|Date of Web Publication||13-Apr-2017|
25 A/1, Pratap Nagar, Khatipura Road, Jaipur - 302 021, Rajasthan
Source of Support: None, Conflict of Interest: None
Tetra-amelia is an extremely rare congenital anomaly. Here, we describe a liveborn neonate with the absence of all four limbs, exstrophy of bladder, cleft lip and palate, dysmorphic face, and other anomalies. This case is reported here because of its rare hereditary occurrence and association with other anomalies.
Keywords: Amelia, cleft lip/palate, limb malformation, Tetra-amelia
|How to cite this article:|
Gupta S, Soni R K, Agrawal V, Agrawal P, Garg P. As rare as Hen's teeth: Tetra-amelia syndrome. J Clin Neonatol 2017;6:103-5
| Introduction|| |
Congenital limb defects have a birth prevalence of 0.55/1000. Amelia, the complete absence of one limb, has a birth prevalence of 0.01/1000 births, in which 50% are syndromic. Tetra-amelia, the complete absence of all four limbs (greek word “tetra” means four and “amelia” means absence of limbs), is even rarer (incidence is of 1.5–4/100,000 births) frequently inherited in an autosomal recessive pattern which occurs due to interruption of development of limb buds between 24 and 36th days of fertilization.,, It is usually described as multiple congenital anomaly syndromes associated with cyclic vomiting syndrome, central nervous system (CNS), gastrointestinal tract, urogenital, craniofacial, or respiratory system malformation., Because newborns with tetra-amelia syndrome have such serious medical problems, most are stillborn or die shortly after birth. The clinical delineation of the different entities associated with tetra-amelia is complex and the molecular findings are limited.
Tetra-amelia syndrome (TAS) has been reported in only a few families worldwide. We describe here a case of live born baby with TAS because of its rarity and its rare associations.
| Case Report|| |
A live neonate, who was few hours old, weighing 2 kg, with the absence of all four limbs, abandoned by parents, was brought into pediatric emergency room by a social worker. Maternal antenatal history was not available in this case.
Examinations revealed complete absence of all four limbs [Figure 1] with bilateral cleft lip and palate, facial dysmorphism, corneal clouding, proptosis, low set ears, short neck exstrophy of bladder, and cloacae with absence of external genitalia. Sex of baby could not be determined.
|Figure 1: Tetra-amelia showing other congenital malformation such as absence of four limbs, cleft lip and palate, exstrophy of bladder|
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On clinical examination, pulmonary and cardiovascular system were normal. There was no abdominal distension or organomegaly. Intravenous access was made in right jugular vein and managed according to protocol. Baby passed meconium on day 1 and vitals were stable after 24 h and started accepting nasogastric feeds since day 2. The baby remained in our neonatal intensive care unit (NICU) for 34 days shown to various specialists and undergone through relevant investigations.
Routine blood investigations were within normal limits. Infantogram showed the absence of all four limbs. Chest X-ray was normal. No abnormality detected in ultrasonography except absence of internal genital organs. ECHO showed a small atrial septal defect. Magnetic resonance imaging (MRI) of the spine showed spina bifida at sacral level with protrusion of neural strands. MRI whole abdomen and magnetic resonance urogram showed nonvisualization of urinary bladder and lower anterior abdominal wall defects with protrusion of bowel loops outside the abdominal wall. Sample for molecular genetic analysis and karyotyping has been sent, report awaited.
On day 35th, as per opinion of various specialists, the baby was referred to higher center for surgical intervention. At the time of referral, baby was vitally stable, weighing 1.7 kg and accepting feeds well.
| Discussion|| |
TAS is a rare congenital defect which takes place between 24 and 36th days after fertilization due to cessation of development of limb buds because of an unidentified cause., It could be a single case or a part of genetic syndrome., Tetra-amelia syndrome is characterized by the complete absence of all four limbs and anomalies involving the cranium and the face (cleft lip/cleft palate, micrognathia, microtia, single naris, choanal atresia, absence of nose); eyes (microphthalmia, microcornea, cataract, coloboma, palpebral fusion); urogenital system (renal agenesis, persistence of cloaca, absence of external genitalia, atresia of vagina); anus (atresia); heart; lungs (hypoplasia/aplasia, diaphragmatic hernia); skeleton (hypoplasia/absence of pelvic bones, absence of ribs, absence of vertebrae); and CNS (agenesis of olfactory nerves, agenesis of optic nerves, agenesis of corpus callosum, hydrocephalus, neural tube defect). Affected infants are often stillborn or die shortly after birth.,
Tetra-amelia can be also a part of several genetic syndromes such as Roberts syndrome, Caudal regression syndrome, Femoral hypoplasia-atypical facial syndrome, Baller-Gerold syndrome, and Hermann-Pallister-Opitz syndrome.
In most cases, even though etiology remains unidentified, a defect in WNT3 gene located at 17q21 which regulates the development of limbs and other organs can lead to this anomaly. Mutations in the WNT3 gene prevent cells from producing functional WNT3 protein, which disrupts normal limb formation and leads to the other serious birth defects associated with tetra-amelia syndrome. Although mode of inheritance is autosomal recessive, in one case, X-chromosome inheritance is also described.
Inspite of difficult peripheral (absence limbs) and central line (short neck) placement, associated congenital defects and feeding problems, management and survival of this baby up to 34 days in our NICU was rewarding in contrast to other reported cases, most of which were either stillborn or die shortly after birth.
Management of patients who survive will depend on the presence and severity of associated malformations and will require the support of multiple medical disciplines. Tetra-amelia is compatible with life if other systems are normal.
Further studies are necessary to make out its exact etiology, risk factors, and mode of inheritance. Antenatal screening, karyotyping analysis, and genetic counseling are recommended to reduce the risk of such congenital anomalies. This case is reported because of its rare occurrence. We should try to identify if there is any role of environmental factors/emerging radiations in causing new mutational changes causing Amelia.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
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Conflicts of interest
There are no conflicts of interest.
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