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Mosaic MECP2 variants in males with classical Rett syndrome features, including stereotypical hand movements
Author(s) -
SchönewolfGreulich Bitten,
Bisgaard AnneMarie,
Dunø Morten,
Jespersgaard Cathrine,
Rokkjær Mette,
Hansen Lars K.,
Tsoutsou Eirini,
Sofokleous Christalena,
Topcu Meral,
Kaur Simran,
Van Bergen Nicole J.,
BrøndumNielsen Karen,
Larsen Martin J.,
Sørensen Kristina P.,
Christodoulou John,
Fagerberg Christina R.,
Tümer Zeynep
Publication year - 2019
Publication title -
clinical genetics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.543
H-Index - 102
eISSN - 1399-0004
pISSN - 0009-9163
DOI - 10.1111/cge.13473
Subject(s) - rett syndrome , mecp2 , mosaic , biology , neuroscience , genetics , physical medicine and rehabilitation , medicine , phenotype , geography , gene , archaeology
Rett syndrome is rarely suspected in males because of the X‐linked dominant inheritance. In the literature, only six male patients have been reported with methyl‐CpG‐binding protein 2 ( MECP2 ) mosaicism. Next‐generation sequencing (NGS) methods have enabled better detection of somatic mosaicism compared to conventional Sanger sequencing; however, mosaics can still be difficult to detect. We present clinical and molecular findings in two males mosaic for a pathogenic MECP2 variant. Both have been reexamined using deep sequencing of DNA isolated from four different cell tissues (blood, muscle, fibroblasts and oral mucosa). Deep sequencing of the different tissues revealed that the variants were present in all tissues. In one patient, the molecular diagnosis could only be established by reexamination after a normal whole exome sequencing, and the other case is an example of reverse genetic diagnostics. Rett syndrome should be considered in males with neurodevelopmental delay and stereotypical hand movements. Subsequent to clinical diagnosis males should be investigated with NGS‐based technologies of MECP2 with high read depth and a low threshold for variant calls. If the initial analysis on full blood derived DNA fails to confirm the suspicion, we recommend repeating the analysis on another tissue, preferentially fibroblasts to increase the diagnostic yield.