Distinct mechanism of formation of the 48, XXYY karyotype

Aránzazu Margallo Balsera,Plácida Sánchez-Giralt,Mayte García De Cáceres,Luz González García,Emilia Balboa Beltrán,Manuela Núñez Estévez,Trinidad Herrera Moreno,Enrique Galán Gómez,José M Carbonell Pérez,Raquel Rodríguez-López

doi:10.1186/1755-8166-6-25

Abstract

BackgroundTo expose the unusual nature of a coincident sex chromosomal aneuploidy in a patient and his father. Molecular mechanisms involved probably are based on the sperm chromosome of paternal origin, which determine the mode of formation. Conventional cytogenetics techniques and multiple Quantitative Fluorescent PCR of STR markers in sexual chromosomes in the patient and his parents.Results48,XXYY and 47,XYY aneuploidies in the patient and his father, respectively, were identified. The additional X and Y chromosomes showed parental origin.ConclusionsAn infrequent origin of the 48,XXYY syndrome was demonstrated. Mostly, it is thought to result from an aneuploid sperm produced through two consecutive non disjunction events in both meiosis I and II in a chromosomally normal father, but in our father’s patient a 47,XYY was discovered. It is suggested that a higher incidence of 24,XY and 24,YY sperm may be possible in 47,XYY individuals andan increased risk for aneuploidy pregnancies may exist. Although 48,XXYY patients and Klinefelter syndrome are often compared, recently they are regarded as a distinct genetic and clinical entity.

Highlights

To expose the unusual nature of a coincident sex chromosomal aneuploidy in a patient and his father
XXYY Syndrome was considered as a variant of the Klinefelter syndrome, but numerous authors have become aware that it has distinctive features. 48,XXYY syndrome the first observation was in 1960 by Muldal and Ockey [1] and later by Court Brown et al [2] was described in 1964 and occurs in an estimated 1:18,000–1:50,000 males [3]
We reported a case of a child with karyotype 48,XXYY, whose neurodevelopment delay, poor motor coordination, behavioral problem, facial features and unilateral kidney was the indication for genetic testing at 7 years of age

Summary

Introduction

To expose the unusual nature of a coincident sex chromosomal aneuploidy in a patient and his father. The 48,XXYY Syndrome is an uncommon sex chromosome aneuploidy condition that is characterized by the presence of one extra X and Y chromosomes in males. When 48,XXYY and 47,XXY patients are clinically compared some differences are found: The first condition shows more frequently facial dysmorphism and congenital malformations [7] and have a lower IQ with frequent and severe behavioral and psychiatric problems, including attention deficit hyperactivity disorder, autism spectrum disorders, and mood and tic disorders [6,7]. Males with sex chromosomal aneuploidies are known to have variability in their developmental profile with the majority presenting with expressive language deficits [6,7,8].

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