European journal of human genetics : EJHG
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Eur. J. Hum. Genet. · Jul 2011
Population frequency of myotonic dystrophy: higher than expected frequency of myotonic dystrophy type 2 (DM2) mutation in Finland.
Myotonic dystrophy (DM) is the most common adult-onset muscular dystrophy with an estimated prevalence of 1/8000. There are two genetically distinct types, DM1 and DM2. DM2 is generally milder with more phenotypic variability than the classic DM1. ⋯ We conclude that the DM2 mutation frequency is significantly higher in the general population (1/1830; P-value = 0.0326) than previously estimated. The identification of DM2 mutations in NMD patients with clinical phenotypes not previously associated with DM2 is of particular interest and is in accord with the high overall prevalence. On the basis of our results, DM2 appears more frequent than DM1, with most DM2 patients currently undiagnosed with symptoms frequently occurring in the elderly population.
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Eur. J. Hum. Genet. · Jul 2011
Analysis of prevalence and degree of macrocephaly in patients with germline PTEN mutations and of brain weight in Pten knock-in murine model.
PTEN Hamartoma Tumour Syndrome (PHTS) includes Cowden syndrome (CS), Bannayan-Riley-Ruvalcaba syndrome (BRRS), and other conditions resulting from germline mutation of the PTEN tumour suppressor gene. Although macrocephaly, presumably due to megencephaly, is found in both CS and BRRS, the prevalence and degree have not been formally assessed in PHTS. We evaluated head size in a prospective nested series of 181 patients found to have pathogenic germline PTEN mutations. ⋯ Macrocephaly, secondary to megencephaly, is an important component of PHTS and more prevalent than previously appreciated. Patients with PHTS have increased risks for breast and thyroid cancers, and early diagnosis is key to initiating timely screening to reduce patient morbidity and mortality. Clinicians should consider germline PTEN testing at an early point in the diagnostic work-up for patients with extreme macrocephaly.