[Trisomy 18 syndrome: A case report]
Wilmar Saldarriaga1, Heidy Rengifo-Miranda2, Julián Ramírez-Cheyne3
1Ginecólogo y obstetra, Magíster en Ciencias Básicas Medicas, Embriología y Genética, Profesor titular, Escuela de Ciencias Básicas Médicas, Universidad del Valle, Cali, Colombia.
Insights
Trisomy 18 syndrome, a genetic disorder, typically has a high infant mortality rate. This case highlights a rare long-term survivor with unique oral cavity features, expanding knowledge of the condition's phenotype.
Area of Science:
- Genetics
- Pediatrics
- Medical Case Reports
Background:
- Trisomy 18 syndrome (Edwards syndrome) results from an extra chromosome 18.
- It affects approximately 1 in 6,000 to 8,000 live births.
- High neonatal and infant mortality rates are characteristic, with few survivors beyond five years.
Observation:
- A 7-year-old female with trisomy 18 presented with significant growth deficiency, psychomotor retardation, and cognitive disability.
- Clinical features included dysmorphic facies, feeding difficulties, hearing loss, ataxia, and cerebellar hypoplasia.
- Unique oral findings included a dome-shaped palate, macroglossia, and absence of specific teeth with delayed eruption.
Findings:
- Karyotype analysis confirmed 47XX+18 in all metaphases.
- The patient exhibited a complex phenotype including severe developmental delays and specific anatomical anomalies.
- Novel oral cavity manifestations, including dental anomalies, were documented.
Implications:
- This case expands the understanding of the trisomy 18 phenotype in long-term survivors.
- The documented oral findings provide new information for clinicians managing these patients.
- Further research is needed to establish the full spectrum of trisomy 18 in older children.
Introduction:
The trisomy 18 syndrome occurs due to the presence of an extra chromosome 18 in most cases. The prevalence in infants is estimated at 1:6000 to 1:8000. Those affected have a high mortality rate, only 4% may survive their first year of life. There are few reported cases exceeding five years of age.
Objective:
The aim of this paper is to report a case of trisomy 18 of long survival with oral cavity features not described in the literature, and to provide information to physicians and paediatricians about aetiology, phenotype, survival and genetic counselling.
Case Report:
A 7 year-old female patient with 2 karyotypes performed by lymphocyte culture showing 47XX+18 in all metaphases. She presented with growth deficiency, dysmorphic facies, severe psychomotor retardation and cognitive disability, inability to feed, lack of verbal language, sensorineural hearing loss, ataxia, cerebellar hypoplasia, and genitals with hypoplastic labia majora and minora. In the oral cavity: dome shaped palate, macroglossia, absence of upper central incisors and first upper and lower molars in mouth. X-ray findings showed formation of missing teeth, with late eruption being concluded.
Conclusions:
In cases of trisomy 18 syndrome there is an increased risk of neonatal and infant mortality. The clinical characteristics in utero and in neonates have been well described. Since few cases exceeding five years of age have been reported, the phenotype is yet to be established. In the case being reported we describe oral cavity findings not documented in the literature.
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