De novo isochromosome 18p in a female dysmorphic child

• Authors: S. Ramegowda , H.M. Gawde , A. Hyderi , M.R. Savitha , Z.M. Patel , B. Krishnamurthy , N.B. Ramachandra
• Languages of publication: EN

Abstracts

EN

Isochromosome 18p results in tetrasomy 18p. Most of the i(18p) cases reported so far in the literature are sporadic due to de novo formation, while familial and mosaic cases are infrequent. It is a rare chromosomal abnormality, occurring once in every 140 000 livebirths, affecting males and females equally. In the present investigation, we report a de novo i(18p) in a female dysmorphic child. The small metacentric marker chromosome was confirmed as i(18p) in the proband by cytogenetic and FISH analysis [47,XX + i(18p)]. Cytogenetic investigations in the family members revealed normal chromosome numbers, indicating the case as a de novo event of i(18p) formation. It could be due to the somewhat advanced maternal age (32 years) and/or expression of recessive genes in the proband, who is the progeny of consanguineous marriage, which could have led to misdivision and nondisjunction of chromosome 18 in meiosis I, followed by failure in the chromatid separation of 18p in meiosis II and by inverted duplication.

Keywords

EN

ISOCHROMOSOME; NONDISJUNCTION; PARENT; RECESSIVE GENE

Discipline

• GENETICS: GENETICS

• Publisher: Institute of Plant Genetics, Polish Academy of Sciences
• Journal: Journal of Applied Genetics
• Year: 2006
• Volume: 47
• Issue: 4
• Pages: 397-401

Contributors

author

S. Ramegowda

author

H.M. Gawde

author

A. Hyderi

author

M.R. Savitha

author

Z.M. Patel

author

B. Krishnamurthy

author

N.B. Ramachandra

• Document Type: ARTICLE
• Publication order reference: N.B. Ramachandra, Human Genetics Laboratory, Department of Studies in Zoology, University of Mysore, Manasagangothri, Mysore 570 006, India