The majority of @entity1 with @entity3148 ( @entity3148 ) are caused by de novo @entity8031 mutations. To investigate the origin of the mutations, we developed and applied a new method that combined deep amplicon resequencing with a Bayesian model to detect and quantify allelic fractions with improved sensitivity. Of 174 @entity8031 mutations in @entity3148 probands which were considered "de novo" by Sanger sequencing, we identified 15 cases (8.6%) of parental mosaicism. We identified another five cases of parental mosaicism that were also detectable by Sanger sequencing. Fraction of mutant alleles in the 20 cases of parental mosaicism ranged from 1.1% to 32.6%. Thirteen (65% of 20) mutations originated paternally and seven (35% of 20) maternally. Twelve (60% of 20) mosaic parents did not have any @entity302 symptoms. Their mutant allelic fractions were significantly lower than those in mosaic parents with @entity302 symptoms (P = 0.016). We identified mosaicism with varied allelic fractions in blood, saliva, urine, hair follicle, oral epithelium, and semen, demonstrating that postzygotic mutations could affect multiple somatic cells as well as germ cells. Our results suggest that more sensitive tools for detecting low-level mosaicism in parents of families with seemingly "de novo" mutations will allow for better informed genetic counseling.

Amplicon Resequencing Identified Parental Mosaicism for Approximately 10% of "de novo" @entity8031 Mutations in XXXX with Dravet Syndrome.

@entity1 :: ('9606', 'Species') :: ['children'] @entity302 :: ('MESH:D004827', 'Disease') :: ['epileptic'] @entity8031 :: ('6323', 'Gene') :: ['SCN1A'] @entity3148 :: ('MESH:D004831', 'Disease') :: ['Dravet syndrome', 'DS']
@entity1 :: (9606,Species) :: ['Children']
