-Gene: DICER1 -PMID: 29343557 -Inheritance Pattern: DICER1 is inherited as an autosomal dominant condition with decreased penetrance -Disease Entity: earlier onset disease, multisite disease, 0-2 site disease, cystic lung disease, familial disease, bilateral disease, stage IA/IB, bilateral disease -mutation: germline loss-of-function mutation, missense mutation, Intronic mutations, hotspot mutation, second somatic mutation, truncating mutations, biallelic mutation -zygosity: heterozygosity -Family History: -testing should be considered for those with a family history of DICER1-associated conditions so that appropriate surveillance can be undertaken. -Individuals at 50% risk of a germline pathogenic variant based on family history who do not pursue genetic testing should follow surveillance guidelines as -if they have a DICER1 mutation unless/until genetic testing confirms that they did not inherit the familial mutation When a pulmonary cyst is identified in a young child with a pathogenic germline -DICER1 variant or family history of a DICER1-associated condition, it should be assumed to be Type I PPB until proven otherwise

Other Information: -Case: Risk for most DICER1-associated neoplasms is highest in early childhood and decreases in adulthood -affected phenotype may simply result from probabilities of generating the characteristic “loss-of-function plus hotspot” two hit typical of a DICER1 syndrome neoplasm. -Caseprevioustesting: presymptomatic testing of a minor child, should be discussed and factored into the decision process, as some individuals may choose, and have the right to choose, not to know their/their child’s genetic status. -gnomAD: n/a