Paternal isodisomy for chromosome 7 and normal growth and development in a patient with congenital chloride diarrhea
- Univ. of Helsinki, (Finland); and others
Uniparental disomy (UPD) has been reported in an increasing number of patients, occasionally ascertained because of concomitant autosomal recessive disorders. In some cases, additional signs such as growth alteration, mental retardation or minor anomalies are present, suggesting an imprinting effect. For maternal chromosome 7, UPD has been described in three patients with recessive disorders. Severe growth retardation diagnosed in all these patients has been explained by the effect of imprinting of growth related genes on maternal chromosome 7. No cases of paternally derived disomy from chromosome 7 were previously known. Here we report paternal isodisomy for chromosome 7 and normal growth in a patient with a recessive disorder, congenital chloride diarrhea (CLD; MIM 214700). Ten informative microsatellite markers on chromosome 7 demonstrated that the proband did not have any maternal contribution to her genotype for that chromosome. Maternal and paternal alleles could not be distinguished for another 10 markers tested for chromosome 7, but the proband was always homozygous. As most uniparental paternal disomies appear to have a postzygotic origin, the primary event might have been a maternal meiotic nondisjunction. A thorough clinical evaluation with a view to additional signs of imprinted genes localized in chromosome 7 was performed. The physical status and laboratory tests were normal except for a mild high-frequency sensorineural hearing loss. As the patient has normal stature, it is likely that the paternal chromosome 7 lacks the suggested maternal imprinting effect on growth. The origin of the hearing loss remains speculative.
- OSTI ID:
- 133620
- Report Number(s):
- CONF-941009--
- Journal Information:
- American Journal of Human Genetics, Journal Name: American Journal of Human Genetics Journal Issue: Suppl.3 Vol. 55; ISSN AJHGAG; ISSN 0002-9297
- Country of Publication:
- United States
- Language:
- English
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