|Year : 2021 | Volume
| Issue : 2 | Page : 83-85
Sclerocornea - A rare manifestation of full trisomy 13
Snehal Ganatra, Shashikant Shetty, P Vijayalakshmi
Department of Pediatric Ophthalmology and Strabismus, Aravind Eye Hospital, Madurai, Tamil Nadu, India
|Date of Submission||24-Jul-2020|
|Date of Decision||20-Aug-2020|
|Date of Acceptance||25-Mar-2021|
|Date of Web Publication||31-Jul-2021|
Department of Pediatric Ophthalmology and Strabismus, Aravind Eye Hospital, Madurai, Tamil Nadu
Source of Support: None, Conflict of Interest: None
Patau syndrome when caused by attachment of an extra chromosome with chromosome 13 is called as full trisomy 13. It is caused by nondisjunction of chromosomes during meiosis. The extra chromosome disrupts normal development, causing multiple and complex organ defects. Children with trisomy 13 are born full term, but they rarely live more than a few days or weeks. Our patient was a 1-year-old female child who presented with various typical and atypical ocular and systemic findings of full trisomy 13. Her karyotyping showed the presence of an extra copy of chromosome 13. Anterior segment dysgenesis is known to occur with Patau's syndrome, but sclerocornea as a manifestation of full trisomy 13 has not been reported prior.
Keywords: Congenital cataract, extra chromosome, Patau's syndrome, sclerocornea, trisomy 13
|How to cite this article:|
Ganatra S, Shetty S, Vijayalakshmi P. Sclerocornea - A rare manifestation of full trisomy 13. J Clin Ophthalmol Res 2021;9:83-5
|How to cite this URL:|
Ganatra S, Shetty S, Vijayalakshmi P. Sclerocornea - A rare manifestation of full trisomy 13. J Clin Ophthalmol Res [serial online] 2021 [cited 2022 Jul 2];9:83-5. Available from: https://www.jcor.in/text.asp?2021/9/2/83/322785
Trisomy 13 was first described in 1960 and is one of the least common trisomies occurring in 1/5000 total births., Patau's features are microcephaly, microphthalmos, iris colobomata, low-set normal ears, harelip, and cleft palate, capillary hemangiomata, polydactyly, long hyperconvex fingernails, talipes equinovarus, and a fibular S-shaped hallucal arch. Median survival time for patients with trisomy 13 is between 7 and 10 days, and it is reported that between 86% and 91% of live-born patients with Patau syndrome More Details do not survive beyond 1 year of life. Because trisomy 13 is often lethal in early infancy, almost all previous reports of ocular anomalies in this condition have been histopathologic descriptions of autopsy specimens. Only a few descriptions of abnormalities in live infants have been reported. Although anterior segment dysgenesis is known to occur in trisomy 13, sclerocornea has not been reported prior. Here in, we report a case of a 1-year-old female child with systemic manifestations, typical and atypical ocular features of full trisomy 13.
| Case Report|| |
A 1-year-old female child was referred to us for cataract surgery. She was the third child of nonrelative healthy parents aged 38 years. Her two other siblings were normal. The child was born at 36 weeks of gestation by an emergency cesarean section in view of severe oligohydramnios, with a birth weight of 2.3 kg.
On examination, there were multiple dysmorphic features-microcephaly, broad receding forehead, cleft lip, cleft palate [Figure 1]a, postaxial polydactyly of all limbs [Figure 1]b and [Figure 1]c, all toes medially deviated with fused nails on both big toes. Echocardiography showed a large atrial and ventricular septal defect with a small patent ductus arteriosus. In addition, she had associated pulmonary hypertension. Neuroimaging showed essentially normal brain parenchyma with bilateral microphthalmia. Renal ultrasound showed bilateral echogenic kidneys. The external genitalia was normal.
|Figure 1: Clinical photograph showing broad receding forehead, cleft lip, and cleft palate (a); polydactyly of all limbs (b and c). Furthermore, karyotyping by fluorescence in situ hybridization analysis showed extra copy of chromosome 13 (d and e)|
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On ocular examination, a jerk nystagmus was noted. Both eyes had microcornea. The right eye showed a corneal opacity, iris coloboma, and absorbed cataractous lens [Figure 2]a. The left eye showed the presence of sclerocornea [Figure 2]a. Bilateral ultrasound B scan showed inferior retinochoroidal coloboma involving disc and macula [Figure 2]b and [Figure 2]c. The axial length was 14.60 mm in the right eye and 16.01 mm in the left eye. Genetic analysis by fluorescent in situ hybridization confirmed the presence of an extra copy of chromosome 13 (Full Trisomy 13) in all cells analyzed [Figure 1]d and [Figure 1]e. The cataract surgery was deferred at this point in time as the parents did not agree for a high-risk consent for general anesthesia in view of pulmonary hypertension.
|Figure 2 : Clinical photograph showing both eyes microcornea with right eye corneal opacity and left eye with sclerocornea (a). Ultrasound B scan showed the presence of bilateral retinochoroidal coloboma (b and c)|
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| Discussion|| |
The cause of Patau syndrome is the presence of three copies of chromosome 13, attributed commonly to nondisjunction in meiosis, occurring frequently in mothers of advanced age (age >35). The major midline dysmorphic features of trisomy 13 are due to a defect in the fusion of the midline prechordal mesoderm in the 1st 3 weeks of gestation, and the defects are more severe than those found in trisomy 18 or 21.
Most published literature has described the histopathologic findings in postmortem eyes because the condition is lethal in early infancy. Ocular abnormalities are frequently found in patients with trisomy 13. Cogan and Kuwabara described a case who had a central corneal opacity, inferonasal iris coloboma with iris strands to the posterior cornea, and a cartilaginous mass behind the angle of anterior chamber in the right eye. The left eye was severely microphthalmic and had an inferonasal iris coloboma, dense cataract, and a cartilaginous mass extending into the chamber angle. Magni et al. reported a 2-year-old patient who had bilateral iris and retinal colobomas and right ectopia lentis. Ultrasonography revealed left microphthalmos with a colobomatous orbital cyst. Lueder reported four cases of Patau syndrome. All four infants had inferonasal iris colobomas with unilateral inferonasal cataracts, primarily involving the posterior lens surface. One patient had persistent hyperplastic primary vitreous and one had Coats' disease. Our patient had all the characteristic ocular findings reported so far and was also noted to have sclerocornea in the left eye.
Infants with Patau syndrome have microcephaly. Facial defects include cleft lip and cleft palate. Central nervous system abnormalities are also usually midline, with alobar holoprosencephaly being the most common defect. Common extremity defects include postaxial polydactyly, congenital talipes equinovarus, or rocker-bottom feet. The spectrum of cardiac disease in Patau syndrome includes a ventricular septal defect, atrial septal defect, tetralogy of Fallot, atrioventricular septal defect, and double outlet right ventricle. Cardiac defects are usually lethal in infancy. Our patient was under treatment for pulmonary hypertension.
When evaluating infants with trisomy 13, surgical intervention is not indicated if the child is unlikely to survive. Since our patient had pulmonary hypertension, we decided not to operate considering that the child had poor visual prognosis and also was a high risk under general anesthesia. In conclusion, our case describes the typical ocular findings in a child with trisomy 13 along with the presence of sclerocornea, an atypical finding associated with Patau syndrome.
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.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2]