49,XXXXY: a distinct phenotype. Three new cases and review.

Abstract

(7Med Genet 1998;35:420-424)

49,XXXXY Syndrome with Diabetes Mellitus

“…Since the first case of 49,XXXXY syndrome was reported in 1960 [10], the clinical features of this syndrome have been described in a number of papers [3, 4, 7,11,12,13,14]. Patients with 49,XXXXY syndrome have not only classic clinical features of Klinefelter syndrome but also some clinical features distinctive from those in Klinefelter syndrome.…”

“…The pentasomy 49,XXXXY has been considered as the most severe variant of Klinefelter syndrome [2], but some reports have delineated the 49,XXXXY syndrome as a separate entity from Klinefelter syndrome [3, 4]. Even though the underlying mechanism of the development of diabetes mellitus is unknown, the incidence of diabetes mellitus among patients with Klinefelter syndrome and other types of X-chromosome polysomy is higher than normal [5, 6].…”

MANAGEMENT OF ENDOCRINE DISEASE: Klinefelter syndrome, cardiovascular system, and thromboembolic disease: review of literature and clinical perspectives

“…Among 3550 KS subjects, Swerdlow et al (7) reported that CCD was the specific cause of mortality in five patients (Standardized Mortality Ratio = 7.3). To the best of our knowledge, all cases of CCD in KS (68,70,71,72,73,74,75,76,77,78,79,80,81,82,83,84,85,86,87,88,89,90,91,92,93,94) are fully reported in the Supplemental Data 1, see section on supplementary data given at the end of this article.…”

49, XXXXY Syndrome with Unilateral Renal Aplasia, Proteinuria, and Venous Thromboembolism

“…Such successive non-disjunction theoretically produces an egg with four X chromosomes, which results in an embryo with 49, XXXXY syndrome, when fertilized by a Y-bearing sperm (2). Since the first case of the 49, XXXXY syndrome was described by Fraccaro et al (3)(4)(5) in [1960][1961][1962], clinical features of this syndrome have been well delineated by different authors (6)(7)(8)(9). Frequent symptoms are mental retardation, peculiar facial features, skeletal malformations affecting particularly the forearms (radioulnar synostosis), and hypoplastic genitals.…”