The contribution of de novo and rare inherited copy number changes to congenital heart disease in an unselected sample of children with conotruncal defects or hypoplastic left heart disease.

Congenital heart disease (CHD) is the most common congenital malformation, with evidence of a strong genetic component. We analyzed data from 223 consecutively ascertained families, each consisting of at least one child affected by a conotruncal defect (CNT) or hypoplastic left heart disease (HLHS) and both parents. The NimbleGen HD2-2.1 comparative genomic hybridization platform was used to identify de novo and rare inherited copy number variants (CNVs). Excluding 10 cases with 22q11.2 DiGeorge deletions, we validated de novo CNVs in 8 % of 148 probands with CNTs, 12.7 % of 71 probands with HLHS and none in 4 probands with both. Only 2 % of control families showed a de novo CNV. We also identified a group of ultra-rare inherited CNVs that occurred de novo in our sample, contained a candidate gene for CHD, recurred in our sample or were present in an affected sibling. We confirmed the contribution to CHD of copy number changes in genes such as GATA4 and NODAL and identified several genes in novel recurrent CNVs that may point to novel CHD candidate loci. We also found CNVs previously associated with highly variable phenotypes and reduced penetrance, such as dup 1q21.1, dup 16p13.11, dup 15q11.2-13, dup 22q11.2, and del 2q23.1. We found that the presence of extra-cardiac anomalies was not related to the frequency of CNVs, and that there was no significant difference in CNV frequency or specificity between the probands with CNT and HLHS. In agreement with other series, we identified likely causal CNVs in 5.6 % of our total sample, half of which were de novo.

Skewed X chromosome inactivation and trisomic spontaneous abortion: no association.

Several studies suggest that highly skewed X chromosome inactivation (HSXI) is associated with recurrent spontaneous abortion. We hypothesized that this association reflects an increased rate of trisomic conceptions due to anomalies on the X chromosome that lead both to HSXI and to a diminished oocyte pool. We compared the distribution of X chromosome inactivation (XCI) skewing percentages (range: 50%-100%) among women with spontaneous abortions in four karyotype groups-trisomy (n = 154), chromosomally normal male (n = 43), chromosomally normal female (n = 38), nontrisomic chromosomally abnormal (n = 61)-to the distribution for age-matched controls with chromosomally normal births (n = 388). In secondary analyses, we subdivided the nontrisomic chromosomally abnormal group, divided trisomies by chromosome, and classified women by reproductive history. Our data support neither an association of HSXI with all trisomies nor an association of HSXI with chromosomally normal male spontaneous abortions. We also find no association between HSXI and recurrent abortion (n = 45).

X-chromosome inactivation and ovarian age during the reproductive years.

OBJECTIVE: To explore whether skewed X-chromosome inactivation (XCI) is related to indicators of ovarian age. DESIGN: The XCI skewing percent and indicators of ovarian age were measured in women with recent pregnancy losses and women with recent livebirths. All analyses adjust for chronologic age and pregnancy outcome. SETTING: Hospital in eastern central New York. PATIENT(S): One hundred thirty-six women with informative XCI assays: 83 with index pregnancy losses and 53 with livebirths. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): The primary indicators of ovarian age were antral follicle count, levels of FSH and inhibin B. A secondary indicator was level of estradiol (E2). RESULT(S): The XCI skewing percent, defined either continuously or categorically (> or =90%), was unrelated to the indicators of ovarian age. The sample was large enough to rule out as unlikely a modest decline in antral follicle count or a modest increase in FSH in relation to skewed XCI. CONCLUSION(S): X-chromosome anomalies are associated with skewed XCI and with premature ovarian failure. Our data raise the possibility that X-chromosome anomalies may not be an important influence on ovarian aging in menstruating women.