Detection and characterization of low‐level mosaicism among clinically unaffected parents of 'sporadic' epidermolysis bullosa simplex cases.

However, no mosaicism was identified in the lymphocytes, hair bulb cells, buccal smear cells and sperm cells of the parents from the other nine trios (Figure 1). The mosaicism was not present by NGS in the lymphocytes, hair bulb cells and buccal smear cells of EB1's father, indicating gonadal mosaicism (Figure 1a). Variants were found only in sperm cells of EB1's father (6-64%) and in buccal smear cells of EB2's father (2-26%), and no variant was detected in other cell samples, indicating those mosaicisms must have occurred late during embryonic development and could not develop the EBS phenotype. [Extracted from the article]