A 45,XX,21--child: attempt at a cytological and clinical interpretation of the karyotype.

Homologous Robertsonian translocation (21q21q) and abortions

“…Expulsion of fetuses at an early gestational age has been attributed to monosomy as they are probably non-viable with the exception of a few rare cases (Gripenberg et al 1972;Dziuba et al 1976;Fryns et al 1977;Wisniewski et al 1983). Trisomies are rare in newborns, which are highly selected products of fertilization.…”

Mosaic Trisomy 21/Monosomy 21 in a Living Female Infant

“…A more devastating effect than a trisomy has a monosomy of the same size and region of the karyotype [Gripenberg et al, 1972;Schinzel, 1993]. Occurrence of a complete autosomal monosomy has only been reported for chromosome 21 since many autosomal monosomies are presumed to end in arrested growth in the first few mitoses, prior even to the time of implantation, with possibly some proceeding to the stage of occult abortion.…”

Monosomy for 21pter-q21: Case report and assignment of a DNA clone (Fr8-77) to the deleted segment

“…When the patterns of QFQ-heteromorphic markers on the maternal and the paternal chromosomes 21 were symbolized as "a, b," and "c, d." respectively, the patient's chromosome 21 showed the "b" pattern (Fig. 4a), indicating that the translocation occurred at Gripenberg et al (1972), Dutrillaux et al (1973), Halloran etal. (1974), Dziuba et al (1976), David et al (1977), Fryns et at.…”

“…When excluding cases of ring chromosome 21 and those of monosomy 21 due to translocation in which break points are ambiguous, 17 cases have been reported. Nine of the 17 cases had partial monosomy for the long-arm of chromosome 21 (Dutrillaux et al, 1973;David et al, 1977;Yamamoto et al, 1979;Modi and Buckton, 1982;Rivera et al, 1983;Wulfsberg et aL, 1983;Yoshimitsu et al, 1983;Ferrante et al, 1983;Reynolds et al, 1985), and the remaining 8 patients were said to have complete monosomy 21 (Gripenberg et al, 1972;Halloran et al, 1974;Dziuba et al, 1976;Fryns et al, 1977;Wisniewski et al, 1983;Herva et al, 1983;Pellissier et al, 1987;Garzicic et al, 1988). However, since complete monosomy 21 is extremely rare even among spontaneous abortuses and these abortuses present severe developmental defects (Ohama and Kajii, 1972;Kuliev et al, 1977), the existence of such newborn infants has remained doubtful (de Grouchy and Turleau, 1984).…”