Authors: Musallam Said Al Araimi , Salwa Ali AlObaidani , Zainab Al Hashmi , Ruba Al Lawati , Hiba Al Mazrooai Al Mazrooai

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Article Info

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Abstract

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Background: The incidence of sex chromosome aneuploidies is 1:400. Klinefelter syndrome is considered to be the most common type of sex chromosome aneuploidy, manifested as variants, such as 48,XXXY, 48,XXYY and 49,XXXXY. Nondisjunction of the X chromosome during meiosis I and II is considered as the cause of this type of aneuploidy. The classic clinical presentation of Klinefelter Syndrome is a triad of hypogonadism, mental retardation, and musculoskeletal anomalies. Case Presentation: In this case report, we describe a 2-year-old male child identified postnatally to have low birth weight, congenital heart defect, inguinal hernia, facial dysmorphism, and genital organs anomalies. Chromosomal analysis revealed a karyotype of 49,XXXXY and the comparative genomic hybridization (CGH) array analysis revealed a 155,065 kilo base pair duplication on chromosome Xp22.33q28 (168,546, −155,233,731) X4. Conclusion: 49,XXXXY karyotype is considered as the rarest sex chromosome aneuploidy syndrome. To our knowledge, this study is the first report of a patient with 49,XXXXY syndrome from Oman.

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Keywords: Aneuploidy, dysmorphism, 49, XXXXY, Klinefelter syndrome

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