Family Relations in the Genomic Era: Communicating about Intergenerational Transmission of Risk for Disability

摘要: Developmental disabilities and sensory impair- ments have a wide range of genetic envi- ronmental causes. Recognized environmental insults include in utero exposure to infections or teratogens (e.g., alcohol, prescription medica- tions, illegal drugs), birth trauma, premature birth. Genetic causes from large genome imbalances (such as Down syndrome, Tri- somy 21, which there is an extra copy entire chromosome) something small one pathogenic DNA variant single gene.Genetic abnormalities can occur de novo (a new abnormality not transmitted either parent) they be inherited several recognizableMendelianpatterns,includingfrom carrier parents who themselves are apparently healthy but increased risk for serious health problem their children. Knowledge about heritable risks has long been interest parents. For the most part, testing disorders historically disease specific, focusing on severely disabling life-threatening conditions such Tay-Sachs cystic fibrosis. But five recent phenomena forced rethinking views practices regarding detection conditions.PHENOMENA AFFECTING DETECTION OF HERITABLE CONDITIONSMore causing disability recognized having componentBasic research underlying processes led identification inheritance mechanisms increasingly number disorders. Bell et al. (2011), drawing data Online Mendelian Inheritance Man (OMIM), reported that 7,028 with suspected inheritance, only 16% (1,139) autosomal recessive (requiring two before manifest children).Complex notions susceptibility riskGenome-wide association studies pro- viding insights into suscepti- bility schizophrenia, bipolar disorder, autism, attention-deficit/ hyperactivity (ADHD; Gershon & Alliey-Rodriguez, 2013). means changes associ- ated elevated disorder at population level. factors determining whether how expressed individual well understood.Although many types intellectual developmental predicted causal component, far fewer cases confidently ascribed gene mutation. Although forms certainly exist, X chromosome harboring genes crucial normal brain development, classified ''familial.'' This classification assumes component present because its occurrence multiple biologic relatives, family history does fit pattern gene. Rather, term multifactorial commonly used describe combination together affected individual. A polygenic score proposed way summarize effects traits no implicated composite components calculated provide overall summary heritability (Dudbridge, Because members share alleles (versions gene) common, it oftendifficulttountangletheirrelevantcausative roles. Hamshere (2013) example associated ADHD, further strengthened if children ADHD also comorbid aggression.Other contributions expression disruptionIt becoming apparent bio- logical physical environment affect expression, phenomenon generally referred ''epigenetics'' (cf. …