McDonald-McGinn Donna M, Zackai Elaine H
Division of Human Genetics, Children's Hospital of Philadelphia, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA.
Dev Disabil Res Rev. 2008;14(1):69-74. doi: 10.1002/ddrr.10.
Because of advances in palliative medical care, children with the 22q11.2 deletion syndrome are surviving into adulthood. An increase in reproductive fitness will likely follow necessitating enhanced access to genetic counseling for these patients and their families. Primary care physicians/obstetric practitioners are in a unique position to identify previously undiagnosed patients as they reach reproductive age and to refer them for genetic counseling. To date, most deletions are de novo, secondary to homologous recombination between low-copy repeat sequences located within 22q11.2. Nonetheless, both somatic and germ line mosaicism has been observed giving unaffected parents a small risk of recurrence. Once present though there is a 50% chance for a person with this contiguous deletion to have an affected child. With this in mind, a variety of prenatal monitoring techniques, as well as, preimplantation genetic diagnosis are available depending on the specific level of risk.
由于姑息性医疗护理的进步，患有22q11.2缺失综合征的儿童正存活至成年期。随着生殖健康状况的改善，这些患者及其家庭对遗传咨询的需求可能会增加。初级保健医生/产科医生处于独特的位置，能够在患者达到生殖年龄时识别出先前未被诊断的患者，并将他们转介进行遗传咨询。迄今为止，大多数缺失是从头发生的，继发于位于22q11.2内的低拷贝重复序列之间的同源重组。尽管如此，已观察到体细胞和生殖系嵌合体现象，这使得未受影响的父母有较小的复发风险。不过，一旦出现这种情况，患有这种连续性缺失的人有50%的几率生育患病子女。考虑到这一点，根据具体风险水平，可采用多种产前监测技术以及植入前基因诊断。
