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Small inherited terminal duplication of 7q with hydrocephalus, cleft palate, joint contractures, and severe hypotonia

Eva Morava1, Oliver Bartsch, Márta Czakó

  • 1University of Pécs, Medical Faculty, Department of Medical Genetics and Child Development, Pécs, Hungary. emorava@yahoo.com

Clinical Dysmorphology
|July 19, 2003
PubMed

Insights

This study identifies a genetic cause for trisomy of distal 7q syndrome in a 14-month-old girl. The findings link a duplication on chromosome 7q to severe hypotonia and distinct facial features.

Area of Science:

  • Genetics
  • Developmental Biology
  • Clinical Genetics

Background:

  • Genetic duplications and deletions can lead to complex congenital disorders.
  • Identifying specific chromosomal regions associated with syndromes aids in diagnosis and understanding pathogenesis.
  • Previous cases of distal 7q duplications presented with overlapping phenotypes.

Observation:

  • A 14-month-old female presented with submucous cleft palate, hydrocephalus, severe hypotonia, and joint contractures.
  • A prior pregnancy showed fetal anomalies including hydrocephalus, cleft palate, and club feet, suggesting an inherited condition.
  • Karyotyping and FISH analysis revealed a duplication of 7q35-qter and a deletion of 13q34-qter in the proband, with a balanced translocation in the mother.

Findings:

  • The proband's genetic abnormality was a duplication of distal 7q (7q35-qter) and a deletion of distal 13q (13q34-qter).
  • The mother carried a balanced translocation, indicating an inherited chromosomal rearrangement.
  • The identified chromosomal region 7q35-qter, potentially including the sonic hedgehog (SHH) gene, is implicated in the observed phenotype.

Implications:

  • This case refines the critical region for 'trisomy of distal 7q' syndrome.
  • The findings highlight the role of the 7q35-qter region, possibly involving the SHH gene, in facial development and muscle tone.
  • Understanding these genetic mechanisms can improve diagnostic accuracy and genetic counseling for families with similar conditions.

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