JAMA : the journal of the American Medical Association
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Germline mutations of the DNA mismatch repair (MMR) genes hMLH1 and hMSH2 have been shown to cosegregate with the colorectal cancer phenotype in multiple hereditary nonpolyposis colorectal cancer (HNPCC) pedigrees. However, the frequency of these mutations among African American patients with colorectal cancer is unknown. ⋯ The results of our analysis support an association between the 3 mutations reported and predisposition to colorectal cancer. Further studies are needed to define DNA MMR gene-associated colorectal cancer in African Americans, an understudied population at increased risk of fatal colorectal cancer.
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Multicenter Study
Preoperative serum potassium levels and perioperative outcomes in cardiac surgery patients. Multicenter Study of Perioperative Ischemia Research Group.
Although potassium is critical for normal electrophysiology, the association between abnormal preoperative serum potassium level and perioperative adverse events such as arrhythmias has not been examined rigorously. ⋯ Perioperative arrhythmia and the need for CPR increased as preoperative serum potassium level decreased below 3.5 mmol/L. Although interventional trials are required to determine whether preoperative intervention mitigates these adverse associations, preoperative repletion is low cost and low risk, and our data suggest that screening and repletion be considered in patients scheduled for cardiac surgery.
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Mutations in the GJB2 gene are the most common known cause of inherited congenital severe-to-profound deafness. The carrier frequency of these mutations is not known. ⋯ Our data suggest that mutations in GJB2 are the leading cause of moderate-to-profound congenital inherited deafness in the midwestern United States. Screening of the GJB2 mutation can be offered to individuals with congenital deafness with high sensitivity and specificity by screening only for the 35delG mutation. A positive finding should establish an etiologic diagnosis and affect genetic counseling.