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[Ring chromosome 13 and multiple malformations (author's transl)]
Insights
A male infant presented with a rare ring chromosome 13, exhibiting severe developmental delays and distinct facial features. This case aligns with clinical characteristics of the 13q deletion syndrome, highlighting genetic disorder complexities.
Area of Science:
- Genetics
- Clinical Medicine
- Pediatrics
Background:
- Ring chromosome 13 is a rare chromosomal abnormality.
- 13q deletion syndrome presents with a spectrum of clinical features.
- Genetic banding techniques are crucial for identifying chromosomal abnormalities.
Observation:
- A male infant presented with a karyotype of 46, XY,r(13)(p12q22), identified via R, D, and G banding.
- Clinical manifestations included severe mental retardation, microcephaly, frontal bossing, a Greek facial profile, micropthalmia, coloboma, high-arched palate, low-set ears, and genital anomalies.
Findings:
- The patient's phenotype closely resembles the first group of 13q deletion syndrome as classified by Niebuhr and Ottosen.
- The identified ring chromosome 13 (r(13)) encompasses segments from both the short (p12) and long (q22) arms.
Implications:
- This case contributes to the understanding of genotype-phenotype correlations in ring chromosome 13.
- Further research into the specific breakpoints and their impact on clinical presentation is warranted.
- The findings highlight the importance of cytogenetic analysis in diagnosing complex genetic syndromes.
Abstract:
A male infant with a ring chromosome identified by R, D and G banding techniques is reported. Karyotype was 46, XY,r(13)(p12q22). The main clinical features were severe mental retardation, microcephaly, frontal bossing a peculiar Greek profile, microphtalmia, coloboma, high and narrowed palate, low-set ears and genital anomalies. The three groups in the 13q deletion syndrome proposed by Niebuhr and Ottosen (1973) are commented. These groups are based on clinical features and loss of segment in the long arms of chromosome 13. Our patient has many of the clinical features of the first group.