Copy number variations (CNVs) detected by CMA (Table 1)
Among 66 cases included in the study cohort, 4 (6%) had a
pathogenic/likely pathogenic CNV; one case of a pathogenic 15Mb terminal
deletion at 18p11.32p11.21, [18p11.32p11.21(136227-15.170,636)x1];
one case of pathogenic 10Mb terminal deletion at
6q23.1q24.[16q23.1q24.1(74,897,270-85,159,980)x1]; one case of
pathogenic 13 Mb interstitial deletion at 1p31.1
[1p31.1(66,634,291-80,128,969)X1] and a fourth case of 571kb
duplication at 5q35.2, classified as likely pathogenic [5q35.2
(176,329,286-176,900,534) x 3]. This last case had a duplication of
the NSD1 gene. In 1 case, a variant of unknown clinical
significance, inherited from the mother, was detected (Table 2). Three
of the 4 pathogenic/likely-pathogenic CNVs were karyotype detectable.
The incremental yield of CMA over karyotype was 1.5%. The rate of
abnormal CMA results was 8% (2/25) in isolated cases and 12.5% (2/16)
in non-isolated cases.