The kidneys play a critical role in maintaining glucose homeostasis.Under normal renal tubular function,most of the glucose filtered from the glomeruli is re-absorbed in the proximal tubules,leaving only trace amounts...The kidneys play a critical role in maintaining glucose homeostasis.Under normal renal tubular function,most of the glucose filtered from the glomeruli is re-absorbed in the proximal tubules,leaving only trace amounts in the urine.Glycosuria can occur as a symptom of generalized proximal tubular dysfunction or when the reabsorption threshold is exceeded or the glucose threshold is reduced,as seen in familial renal glycosuria(FRG).FRG is characterized by persistent glycosuria despite normal blood glucose levels and tubular function and is primarily associated with mutations in the sodium/glucose cotransporter 5A2 gene,which encodes the sodium-glucose cotransporter(SGLT)2.Inhibiting SGLTs has been proposed as a novel treatment strategy for diabetes,and since FRG is often considered an asymptomatic and benign condition,it has inspired preclinical and clinical studies using SGLT2 inhibitors in type 2 diabetes.However,patients with FRG may exhibit clinical features such as lower body weight or height,altered systemic blood pressure,diaper dermatitis,amino-aciduria,decreased serum uric acid levels,and hypercalciuria.Further research is needed to fully understand the pathophysiology,molecular genetics,and clinical manifestations of renal glucosuria.展开更多
Latent autoimmune diabetes in adults (LADA) is an autoimmune diabetes of adult-onset with the presence of diabetes associated autoantibodies. Familial renal glucosuria (FRG) is an inherited renal tubular disorder that...Latent autoimmune diabetes in adults (LADA) is an autoimmune diabetes of adult-onset with the presence of diabetes associated autoantibodies. Familial renal glucosuria (FRG) is an inherited renal tubular disorder that causes persistent isolated glucosuria in the absence of hyperglycemia. We report a novel case of LADA and certain FRG. A 44-year-old man was admitted to our hospital for uncontrolled diabetes. Before admission, he had never suffered from diabetic coma and showed an improvement in HbA1c only with diet therapy. His HbA1c was 11.9% (107 mmol/mol), and anti-glutamic acid decarboxylase antibody was 13.0 U/mL. A glucagon stimulation test showed the decrease of insulin secretion: plasma C-peptide (CPR) 0 min, 0.69 ng/mL;CPR 6 min, 0.90 ng/mL. Analysis of genomic DNA revealed a novel heterozygous mutation in the SGLT2 coding gene, SLC5A2 (c.875G >A, p.Cys292Tyr), which was assessed as probably damaging with a score of 0.998 (sensitivity: 0.27;specificity: 0.99) by an in silico analysis. Therefore, he was diagnosed with LADA and certain FRG. He has not shown any symptoms and his HbA1c improved to 6.4% (46 mmol/mol) three months after the introduction of insulin therapy. Our case clearly implies the clinical effectiveness of SGLT2 inhibition in patients with LADA.展开更多
Arthrogryposis, renal dysfunction and cholestasis (ARC) syndrome (OMIM 208085) is an autosomal recessive disorder that is caused by mutations in 2 interacting genes VPS33B and VIPAS39. Mutations in VPS33B gene account...Arthrogryposis, renal dysfunction and cholestasis (ARC) syndrome (OMIM 208085) is an autosomal recessive disorder that is caused by mutations in 2 interacting genes VPS33B and VIPAS39. Mutations in VPS33B gene account for most cases of ARC. As low or normal gamma-glutamyl transpeptidase (GGT) activity has been described in all patients with ARC syndrome identified so far, ARC syndrome is a possible diagnosis for low GGT cholestasis. Here we describe a Chinese patient with neonatal cholestasis and a high GGT level in three consecutive tests. She had other typical manifestations of ARC syndrome, including arthrogryposis multiplex congenita, renal involvement and ichthyosis. Genetic study of the VPS33B gene further confirmed the diagnosis by identification of compound heterozygosity of two known disease-causing mutations, c.403+2T > A and c.1509-1510insG. The mechanism of high GGT in this patient is unclear. Nevertheless, this case indicates that ARC syndrome cannot be excluded from the differential diagnosis of neonatal cholestasis even if high GGT activity is found.展开更多
文摘The kidneys play a critical role in maintaining glucose homeostasis.Under normal renal tubular function,most of the glucose filtered from the glomeruli is re-absorbed in the proximal tubules,leaving only trace amounts in the urine.Glycosuria can occur as a symptom of generalized proximal tubular dysfunction or when the reabsorption threshold is exceeded or the glucose threshold is reduced,as seen in familial renal glycosuria(FRG).FRG is characterized by persistent glycosuria despite normal blood glucose levels and tubular function and is primarily associated with mutations in the sodium/glucose cotransporter 5A2 gene,which encodes the sodium-glucose cotransporter(SGLT)2.Inhibiting SGLTs has been proposed as a novel treatment strategy for diabetes,and since FRG is often considered an asymptomatic and benign condition,it has inspired preclinical and clinical studies using SGLT2 inhibitors in type 2 diabetes.However,patients with FRG may exhibit clinical features such as lower body weight or height,altered systemic blood pressure,diaper dermatitis,amino-aciduria,decreased serum uric acid levels,and hypercalciuria.Further research is needed to fully understand the pathophysiology,molecular genetics,and clinical manifestations of renal glucosuria.
文摘Latent autoimmune diabetes in adults (LADA) is an autoimmune diabetes of adult-onset with the presence of diabetes associated autoantibodies. Familial renal glucosuria (FRG) is an inherited renal tubular disorder that causes persistent isolated glucosuria in the absence of hyperglycemia. We report a novel case of LADA and certain FRG. A 44-year-old man was admitted to our hospital for uncontrolled diabetes. Before admission, he had never suffered from diabetic coma and showed an improvement in HbA1c only with diet therapy. His HbA1c was 11.9% (107 mmol/mol), and anti-glutamic acid decarboxylase antibody was 13.0 U/mL. A glucagon stimulation test showed the decrease of insulin secretion: plasma C-peptide (CPR) 0 min, 0.69 ng/mL;CPR 6 min, 0.90 ng/mL. Analysis of genomic DNA revealed a novel heterozygous mutation in the SGLT2 coding gene, SLC5A2 (c.875G >A, p.Cys292Tyr), which was assessed as probably damaging with a score of 0.998 (sensitivity: 0.27;specificity: 0.99) by an in silico analysis. Therefore, he was diagnosed with LADA and certain FRG. He has not shown any symptoms and his HbA1c improved to 6.4% (46 mmol/mol) three months after the introduction of insulin therapy. Our case clearly implies the clinical effectiveness of SGLT2 inhibition in patients with LADA.
基金Supported by National Natural Science Foundation of China,No.81070281
文摘Arthrogryposis, renal dysfunction and cholestasis (ARC) syndrome (OMIM 208085) is an autosomal recessive disorder that is caused by mutations in 2 interacting genes VPS33B and VIPAS39. Mutations in VPS33B gene account for most cases of ARC. As low or normal gamma-glutamyl transpeptidase (GGT) activity has been described in all patients with ARC syndrome identified so far, ARC syndrome is a possible diagnosis for low GGT cholestasis. Here we describe a Chinese patient with neonatal cholestasis and a high GGT level in three consecutive tests. She had other typical manifestations of ARC syndrome, including arthrogryposis multiplex congenita, renal involvement and ichthyosis. Genetic study of the VPS33B gene further confirmed the diagnosis by identification of compound heterozygosity of two known disease-causing mutations, c.403+2T > A and c.1509-1510insG. The mechanism of high GGT in this patient is unclear. Nevertheless, this case indicates that ARC syndrome cannot be excluded from the differential diagnosis of neonatal cholestasis even if high GGT activity is found.
