RESUMO
PURPOSE: Germ-line mutations in DICER1 increase the risk of various tumors, including pleuropulmonary blastoma. Macrocephaly and symmetric overgrowth have been reported in some, but not all, patients with mosaic DICER1 RNase IIIb mutations. The prevalence of these features in individuals with constitutional germ-line DICER1 mutations is unknown. METHODS: We analyzed prospectively collected auxology data from 67 DICER1 mutation carriers and 43 family controls. We assessed differences between groups using an exact test for proportions and generalized estimating equations for continuous dependent variables. RESULTS: Twenty-eight DICER1 mutation carriers (42%) were macrocephalic, and none had an occipitofrontal circumference (OFC) below the third centile, which significantly differed from family controls, of whom five were macrocephalic (12%) and two had OFC below the third centile (5%) (P < 0.001). DICER1 mutation carriers were taller than familial controls after controlling for gender (P = 0.048), but similar proportions of both groups were above the 97th centile of population norms. Head circumference remained increased after adjusting for differences in height. CONCLUSION: For the first time, we establish macrocephaly as a common finding in the DICER1 syndrome. Like some other tumor-predisposition disorders, macrocephaly may be a useful, albeit a subtle, clinical clue to the DICER1 syndrome diagnosis.Genet Med 19 2, 244-248.
Assuntos
RNA Helicases DEAD-box/genética , Megalencefalia/genética , Neoplasias/genética , Ribonuclease III/genética , Adolescente , Adulto , Idoso , Estatura/genética , Criança , Pré-Escolar , Feminino , Mutação em Linhagem Germinativa , Heterozigoto , Humanos , Lactente , Masculino , Megalencefalia/diagnóstico , Megalencefalia/fisiopatologia , Pessoa de Meia-Idade , Neoplasias/diagnóstico , Neoplasias/patologia , Blastoma Pulmonar/diagnóstico , Blastoma Pulmonar/genética , Blastoma Pulmonar/fisiopatologiaRESUMO
Context: The risk of thyroid cancer and multinodular goiter (MNG) in DICER1 syndrome, a rare tumor-predisposition disorder, is unknown. Objective: To quantify the risk of thyroid cancer and MNG in individuals with DICER1 syndrome. Design: Family-based cohort study. Setting: National Institutes of Health (NIH) Clinical Center (CC). Participants: The National Cancer Institute DICER1 syndrome cohort included 145 individuals with a DICER1 germline mutation and 135 family controls from 48 families. Interventions: Each individual completed a detailed medical history questionnaire. A subset underwent a 3-day evaluation at the NIH CC. Main Outcome Measures: The cumulative incidence of MNG (or thyroidectomy) was quantified using the complement of the Kaplan-Meier product limit estimator. We compared the observed number of thyroid cancers in the NCI DICER1 cohort with matched data from the Surveillance, Epidemiology, and End Results (SEER) Program. We performed germline and somatic (thyroid cancer, MNG) DICER1 sequencing. Results: By the age of 40 years, the cumulative incidence of MNG or thyroidectomy was 75% in women and 17% in men with DICER1 syndrome compared with 8% of control women (P < 0.001) and 0% of control men (P = 0.0096). During 3937 person-years of observation, individuals with DICER1 syndrome had a 16-fold increased risk of thyroid cancer (95% confidence interval, 4.3 to 41; P < 0.05) compared with the SEER rates. Of 19 MNG nodules and 3 thyroid cancers, 16 (84%) and 3 (100%), respectively, harbored germline and somatic pathogenic DICER1 mutations. Conclusions: We propose a model of thyroid carcinogenesis in DICER1 syndrome. Early-onset, familial, or male MNG should prompt consideration of the presence of DICER1 syndrome.