Retrospective Genetic Analysis of 200 Cases of Sudden Infant Death Syndrome and Its Relationship with Long QT Syndrome in Korea

BACKGROUND: There has been a campaign by the National Education on Sleeping Habits and Living Environment, to reduce the incidence of sudden infant death syndrome (SIDS). However, more than 100 infants die suddenly and unexplainably before the age of 1 year in Korea. Long QT syndrome (LQTS), an inheritable cardiac disease, has been reported to likely be associated with up to 14% of SIDS cases. However, genetic studies of the association between SIDS and LQTS have not yet been conducted in Korea. METHODS: We conducted genetic analysis using genomic DNA extracted from paraffin-embedded tissue blocks from 200 SIDS cases autopsied between 2005 and 2013. We analyzed the following genetic mutations associated with LQTS, KCNQ1, SCN5A, KCNE1, KCNE2, KCNJ2, and CAV3. RESULTS: Of the 200 SIDS cases, 58% involved male infants (116 male and 84 female infants, respectively), the mean age was 140 days (median, 107 days; range, 24–270 days), and they were all of Asian-Korean ethnicity. SIDS IA category criteria comprised 45 cases (22.5%) while the rest were SIDS IB. Fifteen infants (7.5%) had R1193Q in SCN5A, of doubtful pathogenicity, and no pathogenic LQTS variants were observed. CONCLUSION: This genetic investigation of LQTS in SIDS showed a low diagnostic yield. These findings suggest that LQTS molecular autopsy could be cautiously conducted in selected cases with family involvement to improve the available genetic counseling information. Meanwhile, a national SIDS registry should be established to document and evaluate the genetic risk of SIDS in Korea.

A Decline in Renal Function is Associated With Loss of Bone Mass in Korean Postmenopausal Women With Mild Renal Dysfunction

This study was conducted to assess the relationship between estimated glomerular filtration rate (eGFR) and bone mineral density (BMD) in Korean postmenopausal women with mild renal dysfunction. A total of 328 postmenopausal women who underwent BMD measurement during health check-up was investigated. BMD was measured in lumbar spine (L1-L4), femoral neck, total proximal femur and femoral trochanteric areas by dual energy radiography absorptiometry and renal function was estimated by eGFR using Cockcroft-Gault equation. Of the 328 subjects, 317 (96.6%) had an eGFR > or =60 mL/min/1.73 m2. By using simple linear regression analysis, age, height, weight and eGFR were significantly associated with BMD for the 4 aforementioned anatomic sites, while serum levels of creatinine and blood urea nitrogen did not influence BMD. When multiple regression analyses were applied, age and body weight still had significant associations with BMD at 4 different anatomic sites (P < 0.001). A significant association of eGFR with BMD remained in the lumbar spine, femoral neck and proximal total femur (P < 0.05) but not in the trochanteric area (P = 0.300). Our study suggests that a decline of renal function is associated with lower BMD in the lumbar spine, femoral neck and total proximal femur areas in Korean menopausal women with mild renal dysfunction.

Changes in transcript and protein levels of calbindin D28k, calretinin and parvalbumin, and numbers of neuronal populations expressing these proteins in an ischemia model of rat retina / 대한해부학회지

Excessive calcium is thought to be a critical step in various neurodegenerative processes including ischemia. Calbindin D28k (CB), calretinin (CR), and parvalbumin (PV), members of the EF-hand calcium-binding protein family, are thought to play a neuroprotective role in various pathologic conditions by serving as a buffer against excessive calcium. The expression of CB, PV and CR in the ischemic rat retina induced by increasing intraocular pressure was investigated at the transcript and protein levels, by means of the quantitative real-time reverse transcription-polymerase chain reaction, western blot and immunohistochemistry. The transcript and protein levels of CB, which is strongly expressed in the horizontal cells in both normal and affected retinas, were not changed significantly and the number of CB-expressing horizontal cells remained unchanged throughout the experimental period 8 weeks after ischemia/reperfusion injury. At both the transcript and protein levels, however, CR, which is strongly expressed in several types of amacrine, ganglion, and displaced amacrine cells in both normal and affected retinas, was decreased. CR-expressing ganglion cell number was particularly decreased in ischemic retinas. Similar to the CR, PV transcript and protein levels, and PV-expressing AII amacrine cell number were decreased. Interestingly, in ischemic retinas PV was transiently expressed in putative cone bipolar cell types possibly those that connect with AII amacrine cells via gap junctions. These results suggest that these three calcium binding proteins may play different neuroprotective roles in ischemic insult by their ability to buffer calcium in the rat retina.

Renal Vein Thrombosis in Obese Patient / 대한신장학회지

Renal vein thrombosis (RVT) is mostly related with other causes. The underlying conditions of RVT were nephrotic syndrome, trauma, cancer, anatomical anomalies, and other hypercoagulable status. Especially hypercoagulable status was rarely caused by obesity. We diagnosed renal vein thrombosis from an obese patient with hypertriglyceridemia. A male patient visited the Seoul National University Hospital for evaluating the reason of his flank pain. The pain started from two weeks ago, He had regarded flank pain as his obesity status (his weight was 84 kg and Body mass index was 29.41 kg/m2). So he had lost his weight by over-sweating one day before. At initial examination, his blood pressure was 128/75 mmHg, pulse rate was 72/min, respiration rate was 20/min and body temperature was 36.2degrees C. Blood chemistries revealed total cholesterol 218 mg/dL, Blood urea nitrogen/creatinine 12/1.3 mg/dL Urinalysis showed specific gravity 1.015, pH 5.5, protein 2+, blood 2+, RBC/WBC 1-4/<1 HPF on microscopic examination. Twenty-four hour collection of the urine showed protein 329 mg/day, creatinine clearance 90 mL/min. Renal vein thrombosis was visualized on the renal computed tomography and pulmonary embolism on the lung scan. Then, anticoagulant therapy was started after coagulation related tests. However, no abnormality of coagulation tests was detected. The evidence of malignancy was not detected either. After anticoagulation therapy, the pain was subsided. The only underlying cause for his hypercoagulability was considered obese status. Unfortunately we had not checked the triglyceride, initially. So we could not prioritize the reason of renal vein thrombosis into hypertriyglyceridemia. We considered that his obese status and subsequent hypertriyglyceridemia might be one of the causes of renal vein thrombosis.

Characteristics of Severe Hyponatremia in Hospitalized Patients; A Comparison according to the Presence of Liver Disease / 대한신장학회지

PURPOSE: Liver disease is one of the most common causes of hyponatremia and improper management of severe hyponatremia may result in serious complications. We evaluated the prevalence and clinical characteristics of severe hyponatremic patients according to the presence of liver disease in hospitalized patients. METHODS: We studied 12,729 hyponatremic patients during hospitalization in single tertiary referral hospital for 1 year. Hyponatremia was defined as serum sodium level <135 mmol/L and severe hyponatremia as < or =125 mmol/L at least twice. RESULTS: Of 12,729 hyponatremic patients, 711 (0.13%) patients had severe hyponatremia and 290 (40.8%) patients with severe hyponatremia had liver disease. The main cause of severe hyponatremia was liver failure (69.7%) in patients with liver disease and excessive administration of hypotonic fluid (37.3%) in non-liver disease patients. The administration of hypertonic saline was the most common treatment both in liver and non-liver disease group. In severe hyponatremic liver disease patients, the serum sodium level was lower (128.8+/-7.1 at admission, 127.1+/-8.4 at discharge vs 132.1+/-7.5, 131.5+/-8.3 mmol/L) and the duration of severe hyponatremia (5 days vs 3 days) was longer than those in non-liver disease group. Of 589 patients with severe hyponatremic patients who had been treated for the sodium correction, 261 patients were recovered from severe hyponatremia to normal range of serum sodium, and lower correction rate was observed in liver disease group. CONCLUSION: Liver failure was the most common cause of severe hyponatremia in hospitalized patients. Severe hyponatremia in patients with liver disease had poor clinical outcomes.

Etiology and Clinical Outcomes of Renovascular Hypertension / 대한신장학회잡지

BACKGROUND: Renovascular hypertension has variable etiologic diseases and therapeutic outcomes. We performed a retrospective analysis of the causes and treatment results of renovascular hypertension to elucidate long-term prognosis with respect to blood pressure and renal function. METHODS: We reviewed patients who were admitted to Seoul National University Hospital for evaluation of renovascular hypertension in period from January, 1983 to December, 2002. Diagnosis of renovascular hypertension was made by combination of positive functional studies such as captopril renal scintigraphy and/or captopril test and angiographic demonstration of significant stenoses in one or both of renal arteries. Patients who were followed up for more than six months were included and classified according to the etiologic disease and treatment modalities. Responses of blood pressure and renal function in each patient were periodically evaluated. RESULTS: Of 74 patients included, 37 were male and 37 were female. The median age of the patients was 40. Atherosclerotic renal artery stenosis was the most common diagnosis (31, 41.9%), followed by Takayasu's arteritis (21, 28.4%) and fibromuscular dysplasia (14, 18.9%). Control of blood pressure and preservation of renal function were significant in medical, radiological, and surgical therapy group. There was no significant difference in response of blood pressure and renal function to treatment among treatment groups. Poor response of blood pressure and deterioration of renal function were observed more frequently in patients with atherosclerotic renal artery stenosis than in those with Takayasu's arteritis or fibromuscular dysplasia. CONCLUSION: Atherosclerosis was the most common etiologic diagnosis of renovascular hypertension. Medical treatment showed satisfactory treatment results as compared to radiologic and surgical revascularization. Patients with atherosclerotic renal artery stenosis showed poorer control of blood pressure and preservation of renal function.