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[11q distal trisomy due to a familial 11;18 translocation]
I Menéndez1, H Rivera, E Morales
1División de Genética, Instituto Mexicano del Seguro Social, Guadalajara, Jalisco.
Insights
A rare genetic condition, distal trisomy 11q, was observed in a seven-month-old boy. The study indicates the specific duplicated segment (11q23-qter) determines the associated phenotype, regardless of duplication size.
Area of Science:
- Genetics
- Human Molecular Genetics
- Clinical Genetics
Background:
- Distal trisomy 11q is a rare chromosomal abnormality.
- Maternal translocation t(11;18)(q23;p11) can lead to this condition in offspring.
- Understanding the phenotypic consequences of specific trisomic segments is crucial for genetic counseling.
Observation:
- A seven-month-old male infant presented with microbrachycephaly, a long philtrum, a retracted lower lip, and a short neck.
- Clinical examination revealed a cardiac septal defect and psychomotor retardation.
- The patient's condition resulted from a distal trisomy 11q due to maternal balanced translocation.
Findings:
- The observed phenotype in this case of distal trisomy 11q included characteristic facial features and developmental delays.
- The cardiac septal defect suggests potential pleiotropic effects of the chromosomal duplication.
- The study identified a critical region on chromosome 11q involved in the observed phenotype.
Implications:
- The findings suggest that the specific chromosomal segment 11q23----qter is critical for the observed phenotype.
- This implies that the extent of the duplication, as long as it includes this segment, may not significantly alter the clinical presentation.
- Further research into the genes located within the 11q23----qter region is warranted to elucidate the underlying mechanisms of this genetic disorder.
Abstract:
A seven-month-old boy with a distal trisomy 11q resulting from a maternal t(11;18)(q23;p11) is described. His main clinical features were microbrachycephaly, long philtrum, retracted lower lip, short neck, cardiac septal defect, and psychomotor retardation. It is concluded that the phenotype of the trisomy 11q is independent of the size of the duplication whenever the segment 11q23----qter is involved.