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Published on: January 28, 2014
Familial sex chromosomal mosaicism
R C Juberg1, D J Holliday, V S Hennessy
1Department of Obstetrics/Gynecology, Wright State University, Dayton, Ohio.
American Journal of Medical Genetics
|September 1, 1990
Summary
Familial sex chromosomal mosaicism across three generations is rare, presenting diagnostic challenges. This genetic condition primarily impacts fertility, with affected individuals otherwise developing normally.
Area of Science:
- Genetics
- Reproductive Biology
- Human Genetics
Background:
- Familial mosaicism, involving multiple cell lines with different genetic compositions within an individual, is infrequently documented for autosomal or sex chromosomes.
- The accurate diagnosis and prognosis of familial mosaicism are complicated, particularly in prenatal settings.
Observation:
- Three successive generations of females exhibited sex chromosomal mosaicism, characterized by the presence of 3-4 distinct cell lines, with the diploid cell line being the most prevalent.
- The phenotypic impact of this mosaicism appeared minimal, primarily manifesting as reduced fertility in affected females.
Findings:
- The proband, identified through prenatal diagnosis, demonstrated normal growth and developmental milestones.
- A dominant gene mechanism, potentially autosomal or X-linked, is the most probable explanation for the observed familial pattern of sex chromosomal mosaicism.
Implications:
- If a monogenic inheritance pattern is confirmed, the responsible gene's prevalence may be underestimated given the frequency of mosaic cell lines found in amniotic fluid cultures.
- This study highlights the importance of considering familial mosaicism in genetic counseling and prenatal diagnostics, especially when reproductive issues arise.
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