Klinefelter syndrome and associated Fragile‐X syndrome

Abstract

ABSTRACT. During screening of male individuals for Fragile‐X syndrome in a residential facility for persons with mental retardation, the authors found a 21‐year‐old profoundly retarded man who displayed facial features and behaviour suggestive of Fragile‐X syndrome. The chromosome analysis revealed 47, fra(X)(q27)fra(X)(q27)Y. His physically and intellectually normal sister had 14% of X chromosomes with a fragile site. Her two sons, who were subsequently examined, were found to have Fragile‐X syndrome. Thus, the identification of Fragile‐X syndrome in the proband during the screening process of a large institution led to the investigation of the proband's family and the subsequent diagnosis of Fragile‐X syndrome in the proband's two nephews. The ascertainment of the two affected boys permitted prompt introduction of early intervention and special education services. Genetic counselling of other at‐risk family members was carried out.

Folate deficiency drives mitotic missegregation of the human FRAXA locus

“…This leads to FMR1 gene silencing and reduced expression of FMRP protein (25), which is the direct cause of the symptoms associated with FXS (26). Furthermore, ChrX aneuploidy has been observed in female carriers (27) and in male FXS patients (28–30), but the mechanism underlying this form of FRAXA instability also remains unknown. It has been speculated that an atypical DNA structure formed by the CGG repeat itself, such as a hairpin-like structure (31), quadruplex (32), or R loop (33, 34), could contribute to its instability.…”

Fragile X syndrome in Democratic Republic of Congo: dysmorphic, cognitive and behavioral findings in 14 subjects from three families

“…However, karyotyping has not been performed in our patient. To date, the concurrent presence of the fragile-X and the Klinefelter syndromes in the same patient has been found at least 10 times in the available literature (Pueschel, O’brien, et Padre-Mendoza, 1987; Fryns and Van Den Berghe, 1988; Kupke et al , 1991). It has been proven that the incidence of meiotic X chromosome non-disjunction is higher than usual in the heterozygotes for the fra(X) mutation and is a result of maternal non-disjunction (Filippi et al ., 1988).…”

X-linked Chronic Granulomatous Disease in a male child with an X-CGD carrier, Klinefelter brother

“…16 The co-segregation of KS has also been observed at a low frequency in a number of X-linked syndromes. 17,18 One of these, Incontinentia pigmenti (IP) is distinctive in that it is normally fatal in males. 19 Seventy-two male IP patients have been reported and their survival has been attributed to concurrent KS in 8 cases.…”