Figure 1 Panels A–R:

Meiotic outcomes of the proband’s mother’s balanced translocation. Panels A, B, K, and L are the most likely products (normal and balanced) from the proband’s mother’s reciprocal translocation. The Panel L outcome may result in infertility; Panel B may be associated with an abnormal clinical phenotype if the normal X chromosome is not preferentially inactivated; Panel C is known to be viable; Panel M would be expected to have the same degree of viability; Panel D is expected to have a less severe phenotype if the derivative X is preferentially inactivated. The outcomes shown in Panels E, G, I, J, O, and Q are known to be viable, and would be expected to show features of triple X, Turner syndrome or Klinefelter’s syndrome; however, Panels E, G, O, and Q may have a more severe phenotype if the normal X homologues are not inactivated. The outcome shown in Panel N is considered to be less viable and associated with a more severe phenotype. The outcomes shown in Panels F, H, P, and R would result in trisomy 13. Other modes of segregation would have larger imbalances that are considered more unlikely to be viable.