TY - JOUR
T1 - High rate of mosaicism in individuals with Cornelia de Lange syndrome
AU - Huisman, Sylvia A.
AU - Redeker, Egbert J. W.
AU - Maas, Saskia M.
AU - Mannens, Marcel M.
AU - Hennekam, Raoul C. M.
PY - 2013
Y1 - 2013
N2 - Cornelia de Lange syndrome (CdLS) is a well known malformation syndrome for which five causative genes are known, accounting for ∼55-65% of cases. In this study, we hypothesised that mosaicism might explain some of the ∼35-45% of cases without detectable mutation in DNA derived from lymphocytes; we investigated the frequency of NIPBL mutations in buccal cells in individuals negative for mutations in any of the five genes in lymphocytes; and we evaluated the efficiency of obtaining DNA from buccal swabs and the best strategy for optimal mutation detection in CdLS. Buccal swabs were obtained from eight mutation positive and 13 mutation negative individuals with clinically diagnosed CdLS, following informed consent. We then forwarded instructions and a single mouth swab to the families; if subsequently insufficient DNA was obtained, we re-sent two mouth swabs. Buccal cells were screened for NIPBL mutations using Sanger sequencing techniques. Sufficient DNA for analysis was obtained in 21/22 individuals. In all six tested individuals with a known NIPBL mutation and in two with a known SMC1A mutation, the mutation was confirmed in buccal cells. In 10 of the 13 tested individuals without detectable mutation in lymphocytes a NIPBL mutation could be detected in buccal cells. Clinically there were no significant differences between patients with a germline and mosaic NIPBL mutation. Somatic mosaicism for an NIPBL mutation is frequent (10/44; 23%) clinically in reliably diagnosed CdLS individuals. Obtaining buccal swabs at the time a blood sample is obtained will facilitate adequate molecular analysis of clinically diagnosed CdLS patients
AB - Cornelia de Lange syndrome (CdLS) is a well known malformation syndrome for which five causative genes are known, accounting for ∼55-65% of cases. In this study, we hypothesised that mosaicism might explain some of the ∼35-45% of cases without detectable mutation in DNA derived from lymphocytes; we investigated the frequency of NIPBL mutations in buccal cells in individuals negative for mutations in any of the five genes in lymphocytes; and we evaluated the efficiency of obtaining DNA from buccal swabs and the best strategy for optimal mutation detection in CdLS. Buccal swabs were obtained from eight mutation positive and 13 mutation negative individuals with clinically diagnosed CdLS, following informed consent. We then forwarded instructions and a single mouth swab to the families; if subsequently insufficient DNA was obtained, we re-sent two mouth swabs. Buccal cells were screened for NIPBL mutations using Sanger sequencing techniques. Sufficient DNA for analysis was obtained in 21/22 individuals. In all six tested individuals with a known NIPBL mutation and in two with a known SMC1A mutation, the mutation was confirmed in buccal cells. In 10 of the 13 tested individuals without detectable mutation in lymphocytes a NIPBL mutation could be detected in buccal cells. Clinically there were no significant differences between patients with a germline and mosaic NIPBL mutation. Somatic mosaicism for an NIPBL mutation is frequent (10/44; 23%) clinically in reliably diagnosed CdLS individuals. Obtaining buccal swabs at the time a blood sample is obtained will facilitate adequate molecular analysis of clinically diagnosed CdLS patients
U2 - https://doi.org/10.1136/jmedgenet-2012-101477
DO - https://doi.org/10.1136/jmedgenet-2012-101477
M3 - Article
C2 - 23505322
SN - 0022-2593
VL - 50
SP - 339
EP - 344
JO - Journal of medical genetics
JF - Journal of medical genetics
IS - 5
ER -