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Published on: March 15, 2018
Digynic triploid infant surviving for 46 days
T Hasegawa1, N Harada, K Ikeda
1Department of Pediatrics, Keio University School of Medicine, Tokyo, Japan. hasegawa@airmail.net
American Journal of Medical Genetics
|December 10, 1999
Summary
This study details a triploid infant (69,XXX) surviving 46 days, exhibiting Type II phenotype. Findings suggest Type II triploidy originates from maternal meiosis and may lead to longer survival than Type I.
Area of Science:
- Genetics
- Reproductive Biology
- Developmental Biology
Background:
- Triploidy, a chromosomal abnormality where an embryo has three sets of chromosomes, is typically lethal.
- Type II triploidy is characterized by specific phenotypic features and is often associated with maternal origin.
Observation:
- A triploid infant (69,XXX) with severe intrauterine growth retardation and macrocephaly survived for 46 days.
- Karyotype analysis of multiple tissues confirmed nonmosaic triploidy.
- Parental DNA analysis indicated the extra chromosome set resulted from maternal second meiotic nondisjunction.
Findings:
- The infant's phenotype was consistent with Type II triploidy.
- Literature review revealed five triploid infants surviving over four weeks, with four being digynic and one diandric.
- This case supports the hypothesis that digynic triploidy (Type II) has a longer survival rate compared to diandric triploidy (Type I).
Implications:
- Understanding the parental origin of triploidy is crucial for predicting clinical outcomes.
- Further research into the genetic and developmental factors influencing triploidy survival is warranted.
- This case contributes to the understanding of chromosomal abnormalities and their impact on fetal development and survival.
