Trisomy 21 and Rett syndrome: a double burden
H Leonard1, L Weaving, P Eastaugh
1Centre for Child Health Research, The University of Western Australia, Telethon Institute for Child Health Research, Perth, Western Australia. hleonard@ichr.uwa.edu.au
Insights
This study reports a rare case of a girl diagnosed with both Down syndrome and Rett syndrome. The findings highlight that having one neurodevelopmental disorder does not exclude a diagnosis of Rett syndrome.
Area of Science:
- Genetics
- Neurodevelopmental Disorders
- Pediatrics
Background:
- Rett syndrome is a severe neurodevelopmental disorder primarily affecting girls, characterized by regression of skills and stereotyped movements.
- Mutations in the methyl-CpG binding protein 2 (MECP2) gene are identified in up to 80% of classical Rett syndrome cases.
Observation:
- A girl with Down syndrome (trisomy 21) exhibited symptoms highly suggestive of Rett syndrome from 18 months of age.
- Clinical diagnosis of Rett syndrome was suspected for years before laboratory confirmation.
- The patient was found to have both trisomy 21 and a specific mutation (R168X) in the MECP2 gene.
Findings:
- Confirmed dual diagnosis of Down syndrome and Rett syndrome in a single patient.
- Identified an R168X mutation in the MECP2 gene in conjunction with trisomy 21.
- Demonstrated that the presence of Down syndrome does not preclude a diagnosis of Rett syndrome.
Implications:
- This case expands the understanding of the genetic and clinical spectrum of Rett syndrome.
- Highlights the importance of comprehensive genetic testing in complex neurodevelopmental presentations.
- Suggests that co-occurrence of neurodevelopmental disorders may be more common than previously recognized.
Abstract:
Rett syndrome is a severe neurodevelopmental disorder generally affecting girls. Affected individuals are apparently normal at birth but later pass through a period of regression with loss of hand and communication skills and the development of hand stereotypies and dyspraxia. Mutations in the methyl-CpG binding protein 2 (MECP2) gene, have now been found to cause Rett syndrome in up to 80% of classical cases. We report a girl with Down syndrome, one of three children with birth defects in a family of five. From the age of 18 months she developed symptomatology considered by her primary physician to be very characteristic of Rett syndrome. However, this remained a clinical diagnosis till the age of 12 years. Laboratory confirmation of the dual diagnosis, which includes a R168X mutation in the MECP2 gene in addition to trisomy 21, has now been possible. The presence of one neurological or developmental disorder does not necessarily preclude a diagnosis of Rett syndrome.
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