Hegmann K M, Spikes A S, Orr-Urtreger A, Shaffer L G
Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA.
Am J Med Genet. 1996 Jan 2;61(1):10-5. doi: 10.1002/(SICI)1096-8628(19960102)61:1<10::AID-AJMG2>3.0.CO;2-0.
A genetics evaluation was requested for a 6-week-old infant with multiple congenital malformations including mild craniofacial anomalies, truncal hypotonia, hypospadias, and a ventriculoseptal defect. Blood obtained for chromosome analysis revealed an abnormal chromosome 4. Paternal chromosome analysis showed a 46,XY, inv ins (3;4)(p21.32;q25q21.2), inv(4)(p15.3q21.2) karyotype. Therefore, the proband's chromosome 4 was the unbalanced product of this insertional translocation from the father resulting in partial monosomy 4q. Additionally, the derivative 4 had a pericentric inversion which was also seen in the father's chromosome 4. During genetic counseling, the proband's 2-year-old brother was evaluated. He was not felt to be abnormal in appearance, but was described as having impulsive behavior. Chromosome analysis on this child revealed 46,XY,der(3)inv ins(3;4)(p21.32;q25q21.2)pat. This karyotype results in partial trisomy 4q. FISH using two-color "painting" probes for chromosomes 3 and 4 confirmed the G-banded interpretation in this family. The segregation seen in this family resulted in both reciprocal products being observed in the two children, with partial 4q monosomy showing multiple congenital anomalies, and partial 4q trisomy showing very few phenotypic abnormalities.
一名6周大的婴儿因多种先天性畸形接受了遗传学评估，这些畸形包括轻度颅面异常、躯干肌张力减退、尿道下裂和室间隔缺损。用于染色体分析的血液检测显示4号染色体异常。父亲的染色体分析显示核型为46,XY, inv ins (3;4)(p21.32;q25q21.2), inv(4)(p15.3q21.2)。因此，先证者的4号染色体是来自父亲的这种插入性易位的不平衡产物，导致4q部分单体性。此外，衍生的4号染色体有一个臂间倒位，这在父亲的4号染色体中也可见。在遗传咨询期间，对先证者2岁的弟弟进行了评估。他外观上未被认为异常，但被描述有冲动行为。对这个孩子的染色体分析显示为46,XY,der(3)inv ins(3;4)(p21.32;q25q21.2)pat。这种核型导致4q部分三体性。使用针对3号和4号染色体的双色“描绘”探针进行的荧光原位杂交（FISH）证实了该家族中G显带的解读。在这个家族中观察到的分离现象导致在两个孩子中都观察到了相互的产物，4q部分单体性表现出多种先天性异常，而4q部分三体性表现出很少的表型异常。
