Figure 2

Schematic representation of a t(X;A) transmission. Autosomes are blue, active X chromosome and Y chromosome are grey, inactive X chromosome is striped in black. Top: balanced t(X;A) in the mother, with usual pattern of inactivation (normal X inactivated). Transmission in male: a) normal; b) balanced translocation; c) unbalanced translocation with derivative autosome, leading to functional X disomy; d) unbalanced translocation with derivative X, leading to partial X monosomy and partial autosomal trisomy; a and b are associated to a normal phenotype, c and d to an abnormal phenotype. Transmission in female: a) normal; b) balanced translocation with normal X inactivated; c) unbalanced translocation with derivative autosome, leading to partial autosomal monosomy and to functional X disomy; d) unbalanced translocation with derivative X leading to partial X monosomy and partial autosomal trisomy; e) balanced translocation with rare inactivation pattern (der(X) inactivated) leading to functional disomy and potential inactivation spreading to translocated autosomal genes; a and b are associated to a normal phenotype; c, d and e to an abnormal phenotype.