Abstract
The t(11;22) rearrangement is the most common recurrent familial reciprocal translocation
in man. Heterozygote carriers are phenotypically normal but are at risk of subfertility
in the male, miscarriages, and producing chromosomally unbalanced offspring. The unbalanced
progeny usually results from an extra der(22) chromosome resulting from a 3:1 malsegregation.
We present here a family with t(11;22). Of six siblings, three were found to be carriers
following prenatal diagnosis of the proband fetus. Neither of the two married carrier
siblings have a live born child. In keeping with the prevailing knowledge of the pregnancy
outcomes of heterozygote carriers, between the siblings they had recurrent miscarriages,
a fetus with a +der(22) chromosome, and other subfertility issues resulting in multiple
failed in vitro fertilization cycles with preimplantation genetic diagnosis. However,
unlike the siblings, their extended family comprising their heterozygote translocation
mother, married aunts and an uncle had normal fertility and a lack of a history of
miscarriages or an abnormal child. The differing outcomes may be related to the male
partners having additional semen anomalies which may further exacerbate problems associated
with the t(11;22). Because the t(11;22) rearrangement tends to run in families, it
is recommended that chromosome studies are offered to family members of an affected
relative as an option, and provide them with appropriate genetic counseling so that
they will have the necessary information with regard to their risk for subfertility,
miscarriages, and production of viable unbalanced offspring. Follow-up prenatal diagnosis
should also be offered to affected expectant family members, especially after preimplantation
genetic diagnosis.
Keywords
Emanuel syndrome - subfertility - miscarriage - preimplantation genetic diagnosis
- +der(22)t(11;22) syndrome
