First cryptic balanced reciprocal translocation mosaicism and familial transmission.

摘要

Cryptic subtelomeric chromosome rearrangements may account for as much as 6-10% of idiopathic moderate to severe mental retardation (MR). Approximately 40% of subtelomeric abnormalities appear to be inherited from one of the parents carrying a balanced chromosome rearrangement [Knight et al., 1999; Riegel et al., 2001]. Mosaicism for balanced or unbalanced structural aberrations in man is extremely a rare phenomenon [Kleczkowska et al., 1990] or may be under-diagnosed. The mechanism, prevalence, and clinical significance of this type of chromosomal anomaly are not well known [Farrell, 1991; Petkovic et al., 2003]. Balanced reciprocal translocation mosaicism has been reported in only 23 cases to our knowledge [Stenchever et al., 1977; Sciorra et al., 1985; Cantu and Ruiz, 1986; Fryns and Kleczkowska, 1986; Saura et al., 1987; Castle and Bernstein, 1988; Kleczkowska et al., 1990; Farrell, 1991; Sciorra et al., 1992; Aughton et al., 1993; Gardner et al., 1994; Opheim et al., 1995; Leegte et al., 1998; Vargas and Fernandez-Novoa, 2001].