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Maternal isochromosome 7q and paternal isochromosome 7p in a boy with growth retardation

D Kotzot1, H Holland, E Keller

  • 1Institute for Human Genetics, University of Leipzig, Leipzig, Germany.

American Journal of Medical Genetics
|July 31, 2001
PubMed

Insights

This study reports a boy with growth retardation and specific facial features, linked to unusual chromosome 7 arrangements. Findings suggest maternally imprinted genes on chromosome 7 long arm influence postnatal growth.

Area of Science:

  • Genetics
  • Human Molecular Genetics
  • Pediatric Endocrinology

Background:

  • Postnatal growth retardation can stem from various genetic factors.
  • Chromosome abnormalities, including isodisomy, are implicated in developmental disorders.
  • Imprinted genes play crucial roles in regulating fetal and postnatal growth.

Observation:

  • A 12-year-old boy presented with postnatal growth retardation, minor facial anomalies (triangular face, small nose, high-arched palate), and normal psychomotor development.
  • Constitutional karyotype revealed an isochromosome 7p and 7q (46,XY,i(7)(p10),i(7)(q10)).
  • Molecular analysis confirmed maternal isodisomy for 7q and paternal isodisomy for 7p.

Findings:

  • The patient's clinical presentation and molecular genetic findings (maternal 7q isodisomy, paternal 7p isodisomy) are consistent with previously reported cases.
  • These findings support the existence of maternally imprinted gene(s) on the long arm of chromosome 7 (7q).
  • These imprinted genes appear to regulate postnatal growth.

Implications:

  • This case reinforces the hypothesis of maternally imprinted genes on chromosome 7q affecting postnatal growth.
  • Understanding these imprinted genes can aid in diagnosing and potentially managing growth disorders.
  • Further research into chromosome 7 imprinting is warranted for pediatric growth studies.

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