Does bilirubin level correspond to interaction of c.-3279T>G and A(TA)7TAA variants in UGT1A1 gene?

Promoter variants c.-3279T>G and A(TA)7TAA show decreased level of expression of UDP-glucuronosyl transferase 1A1 (UGT1A1) and consequently reduced activity of the enzyme catalyzing glucuronidation of bilirubin in hepatocytes. Thus, coincidental occurence of both variants should lead to increase of hyperbilirubinemia or contribute to its manifestation. In this study, investigation of both variants in 101 patients and 84 controls in a Caucasian population was performed and the results were compared with serum bilirubin levels. Despite high linkage disequilibrium between the loci (D' = 0.91, r(2) = 0.69), we have proven an interaction between the variants increasing the odds ratio for [(TA)7]+c.[-3279T>G] homozygotes to 54.2.

[Juvenile hyperbilirubinaemia and its early manifestation in adolescence]. / Juvenilní hyperbilirubinémie a její iniciální projevy v dorostovém veku.

Mild isolated unconjugated hyperbilirubinaemia is incidentally or purposefully attained finding in 4-8% of population. Adolescence is a typical age for detection of hypebilirubinaemia. In these patients a mutation in gene-promoter for uridin-diphospho-glucuronyl-transpherase A 1, which determines development of the benign Gilbert's syndrome, is present in most of the cases. Although homozygote formation of this mutation was described in 11-16% of general population, only in a part of them hyperbilirubinaemia is manifested. Beginning or continuation of hyperbilirubinaemia in adolescent age is linked probably with some other changes in the hepatocyte and factors which influence it. Among adolescents with hyperbilirubinaemia, risk factors that can induce a metabolic liver overload have to be considered. They include oligosymptomatic or asymptomatic EBV infection, drug and alcohol abuse, hormonal contraception etc. These conditions must be respected in the regimen of these adolescents.

Importance of serum bile acids determination in adolescents with juvenile hyperbilirubinaemia.

The aim of the study was to identify moderate liver impairment in a group of hyperbilirubinaemic adolescents. Using gas chromatography we assessed both total bile acid and primary bile acid levels in 50 adolescents with juvenile hyperbilirubinaemia. At the same time we performed hepatologic examinations and subsequent follow-up assessment of these patients for a period of at least 2 years. As a control group we examined 30 adolescents without any impairment of both the liver and gastrointestinal tract, and 18 patients with low grade (moderately) active chronic hepatitis. In both groups we assessed total and primary bile acids levels as well as conventional liver tests (bilirubin, ALT, AST). On the basis of the clinical course and laboratory findings we divided our patients with juvenile hyperbilirubinaemia into two groups: a group of individuals with Gilbert's syndrome (30 patients) and a group of individuals with probable moderate liver impairment (20 patients). The latter group consisted of the adolescents who exhibited bilirubinaemia over 90 micromol/l and/or exhibited hepatomegaly or splenomegaly proved by the ultrasound examination and/or exhibited intermittent elevation of the liver aminotransferases serum levels. In the group of individuals with moderate liver impairment serum total bile acid levels were significantly elevated in 26% of patients, and the serum cholic acid level was significantly elevated in 25% of patients. These two parameters mutually correlated at a high level of significance. Juvenile hyperbilirubinaemia is one of the common conditions of adolescent age. Its etiology is diverse; it includes both benign conditions like Gilbert's syndrome and post-hepatitic and toxic conditions that require a long-term regimen and follow-up examinations. The number of people suffering from juvenile hyperbilirubinaemia has been growing in the population. Currently 4-6% of the adolescent population suffers from this disease. This growing number is probably caused by external factors of our environment (infection, toxic effects). The determination of mild liver disease in hyperbilirubinaemic patients and the provision of an adequate regimen of exercise and adequate nutritional measures is of great importance for the health of the adolescent population.

Pseudohypoparathyroidism type IA and II with severe neuropsychic manifestations.

Pseudohypoparathyroidism (PHP) is characterized by unresponsiveness of target tissues to the biological actions of the parathyroid hormone (PTH), with resulting hypocalcemia and hyperphosphatemia, despite the elevated serum levels of PTH. PHP is divided into types Ia, b, c and II, depending on the presence of Albright's hereditary osteodystrophy (AHO), defective urinary excretion of phosphate (U-P) and response in urinary excretion of cyclic adenosine monophosphate (U-cAMP) after the administration of exogenous PTH. Patients with PHP might exhibit various manifestations of neuropsychic disturbances. We present two boys, aged 14 and 16 years, both with paresthesia, anxiety and epilepsy; the former patient also suffered from mild mental retardation. In both patients, hypocalcemia and hyperphosphatemia together with increased serum levels of PTH suggested the diagnosis of PHP. After administration of exogenous PTH (Ellsworth-Howard test), there was a drop in U-P in both patients, while U-cAMP was decreased in the first patient and increased in the second one, thus confirming the diagnoses of PHP Ia and II, respectively. Neuropsychic disturbances and epilepsy resolved completely in both patients after treatment with calcium and dihydrotachysterol. Evaluation of calcemia and phosphatemia should be mandatory in all patients with neuropsychic disorders. Ellsworth-Howard test remains a useful tool in the differential diagnosis of PHP.

Dent's disease--the hypercalciuric variant of Fanconi's syndrome.

Dent's disease is a rare type of proximal renal tubular defect characterized by hypercalciuria, low-molecular-weight (LMW) proteinuria, nephrocalcinosis and slowly progressive renal failure, short stature and osteopenia in children with clinical symptoms of rickets. This "hypercalciuric rickets" was originally described by Charles Dent and Max Friedman in 1964 [1]. The disease is probably linked to the X chromosome so that males are much more severely affected than females.

Two cases of pseudohypoparathyroidism in adolescent boys.

Pseudohypoparathyroidism (PHP) is characterized by end organ resistance to parathyroid hormone (PTH). PHP type Ia consists of Albright's osteodystrophy and resistance to PTH. In PHP type Ib physical appearance is normal and there is no response to PTH in U-cAMP excretion. In PHP type II both physical appearance and U-cAMP response to PTH infusion are normal. Two adolescent patients with severe hypocalcaemia were treated in our department. The first boy was admitted because of low back pain, latent tetany and recurrent collapsing, the second one due to Grand mal epilepsia. S-Ca concentrations were very low (1.1 and 1.03 mmol/l respectively), CT of the brain revealed multiple calcifications in basal ganglia and S-PTH concentrations were above upper reference level. Therefore the diagnosis of PHP was established. In the absence of skeletal malformations the most probable diagnosis is PHP Ib or II. Clinical state of the boys has dramatically improved after calcium and vitamin D supplementation.