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Chromosome 7 abnormalities in parents of children with holoprosencephaly and hydronephrosis
I W Lurie1, H G Ilyina, L V Podleschuk
1Byelorussian Institute for Hereditary Diseases, Minsk, USSR.
Insights
Holoprosencephaly (HPE) is linked to deletions on chromosome 7q (del(7q)). This genetic imbalance, particularly del(7q), is associated with severe HPE forms like cyclopia, impacting early brain development.
Area of Science:
- Genetics
- Developmental Biology
- Clinical Medicine
Background:
- Holoprosencephaly (HPE) is a severe congenital disorder characterized by incomplete separation of the forebrain.
- Previous literature reports link HPE to specific chromosomal deletions on the long arm of chromosome 7 (7q).
Purpose of the Study:
- To investigate the association between chromosome 7q deletions and holoprosencephaly.
- To identify potential genetic factors contributing to the development of HPE.
Main Methods:
- Analysis of balanced chromosomal rearrangements in mothers of infants with HPE and hydronephrosis.
- Review of existing literature on HPE and 7q deletions.
Main Results:
- Identified balanced rearrangements [inversion (7)(p22.1q34) and translocation (4;7)(q31;q36)] in two mothers.
- Del(7q) was the most probable chromosomal imbalance in these cases.
- Confirmed a strong association between HPE and del(7q).
Conclusions:
- The data support a significant link between holoprosencephaly and chromosome 7q deletions.
- Del(7q) may play a crucial role in arresting early prosencephalon development, leading to severe HPE phenotypes such as cyclopia and cebocephaly.
Abstract:
At least nine cases of holoprosencephaly (HPE) found in patients with confirmed loss of 7q34----7qter or 7q36----7qter have been reported in the literature. In the present report, balanced rearrangements involving chromosome 7q [inv(7)(p22.1q34) and t(4;7)(q31;q36)] were shown in two mothers examined after the birth of their non-karyotyped infants with HPE and hydronephrosis. In both cases, del(7q) was the most probable imbalance. The available data confirm the association between HPE and del(7q). Predominance of cyclopia and cebocephaly, the severest forms of HPE, suggests that del(7q) may be an important factor in arresting prosencephalon development at the earliest stages.