Schneider A S, Bischoff F Z, McCaskill C, Coady M L, Stopfer J E, Shaffer L G
Department of Pediatrics, Albert Einstein Medical Center, Philadelphia, Pennsylvania, USA.
Am J Med Genet. 1996 Dec 11;66(2):204-8. doi: 10.1002/(SICI)1096-8628(19961211)66:2<204::AID-AJMG16>3.0.CO;2-X.
Uniparental disomy for chromosome 16 has been previously identified in fetal deaths and newborn infants with limited follow-up. Thus there is a lack of information about the long-term effects of maternal uniparental disomy 16 on growth and development. We present a case of maternal heterodisomy for chromosome 16 and a comprehensive 4-year physical and cognitive evaluation. Cytogenetic analysis of chorionic villus obtained at 10 weeks gestation for advanced maternal age showed trisomy 16. At 15 weeks, amniocentesis demonstrated low level mosaicism 47,XY,+16[1]/46,XY[25]. Decreased fetal growth was noted in the last 2 months of pregnancy and the infant was small for gestational age at birth. Molecular studies revealed only maternal alleles for chromosome 16 in a peripheral blood sample from the child, consistent with maternal uniparental heterodisomy 16. Although short stature remains a concern, there appears to be no major cognitive effects of maternal disomy 16. Clinical evaluation and follow-up on additional cases should further clarify the role of placental mosaicism and maternal disomy 16 in intrauterine growth retardation and its effects on long-term growth in childhood.
此前，在随访有限的死胎和新生儿中已发现16号染色体单亲二体。因此，关于母亲16号染色体单亲二体对生长发育的长期影响，目前还缺乏相关信息。我们报告了一例母亲16号染色体异源二体的病例，并进行了为期4年的全面体格和认知评估。因母亲高龄，在孕10周时获取绒毛膜绒毛进行细胞遗传学分析，结果显示为16三体。孕15周时，羊水穿刺显示为低水平嵌合体47,XY,+16[1]/46,XY[25]。妊娠最后2个月发现胎儿生长减缓，婴儿出生时为小于胎龄儿。分子研究显示，患儿外周血样本中16号染色体只有母亲的等位基因，符合母亲16号染色体异源单亲二体。尽管身材矮小仍是一个问题，但母亲16号染色体单亲二体似乎没有重大认知影响。对更多病例的临床评估和随访应能进一步阐明胎盘嵌合体和母亲16号染色体单亲二体在宫内生长迟缓中的作用及其对儿童期长期生长的影响。
