The Level of Serum and Urinary Nephrin in Normal Pregnancy and Pregnancy with Subsequent Preeclampsia

PURPOSE: The aim of this study was to evaluate serum and urinary nephrin levels of normal pregnancy to establish a standard reference value and to compare them with patients who subsequently developed preeclampsia (PE). MATERIALS AND METHODS: In this prospective study, 117 healthy singleton pregnancies were enrolled between 6 to 20 weeks of gestation at 2 participating medical centers during October 2010 to March 2012. Urine and serum samples were collected at the time of enrollment, each trimester, and at 4 to 6 weeks postpartum. Enzyme-linked immunosorbent assay for nephrin was performed and samples from patients who subsequently developed PE were compared to the normal patients. RESULTS: Of 117 patients initially enrolled, 99 patients delivered at the study centers and of those patients, 12 (12.1%) developed PE at a median gestational age of 34⁺⁴ weeks (range 29⁺⁵–36⁺⁶). In the normal patients (n=68), serum nephrin level decreased and urinary nephrin level increased during the latter of pregnancy. In 12 patients who subsequently developed PE, a significant rise in the 3rd trimester serum and urinary nephrin levels, compared to the controls, was observed (p<0.001), and this increase occurred 9 days prior to the onset of clinical disease. CONCLUSION: As the onset of PE was preceded by the rise in the serum and urinary nephrin in comparison to normal pregnancy, serum and urinary nephrin may be a useful predictive marker of PE.

Carrier frequency of SLC26A4 mutations causing inherited deafness in the Korean population

PURPOSE: The mutation of the SLC26A4 gene is the second most common cause of congenital hearing loss after GJB2 mutations. It has been identified as a major cause of autosomal recessive nonsyndromic hearing loss associated with enlarged vestibular aqueduct and Pendred syndrome. Although most studies of SLC26A4 mutations have dealt with hearing-impaired patients, there are a few reports on the frequency of these mutations in the general population. The purpose of this study was to evaluate the prevalence of SLC26A4 mutations that cause inherited deafness in the general Korean population. MATERIALS AND METHODS: We obtained blood samples from 144 Korean individuals with normal hearing. The samples were subjected to polymerase chain reaction to amplify the entire coding region of the SLC26A4 gene, followed by direct DNA sequencing. RESULTS: Sequencing analysis of this gene identified 5 different variants (c.147C>G, c.225G>C, c.1723A>G, c.2168A>G, and c.2283A>G). The pathogenic mutation c.2168A>G (p.H723R) was identified in 1.39% (2/144) of the subjects with normal hearing. CONCLUSION: These data provide information about carrier frequency for SLC26A4 mutation-associated hearing loss and have important implications for genetic diagnostic testing for inherited deafness in the Korean population.