[Kalmann syndrome in monozygous twins as an isolated manifestation of the SOX10 gene defect].

More than 30 genes are known to take part in hypothalamic-pituitary-gonadal axis development at the date and role of more than 10 other genes is studied. Despite it about 50% of isolated hypogonadotropic hypogonadism cases still have no molecular genetic explanation.A number of specific associations between iHH and different not-reproductive manifestations called syndromic forms are distinguished in general group of iHH. For example, the combination of Kalmann syndrome with sensorineural hearing loss is known as manifestation for defects of some genes encoding factors of neuronal migration; in patients with this phenotype CHD7, SOX10 genes defects are most frequent. However, defects in the genes of neuronal migration factors are characterized by a wide variability of phenotype, which is explained by the epigenetic mechanisms influence. Carriers of the mutation within the same family may lack some non-reproductive manifestations as well as hypogonadism.Here we present a case of Kalmann syndrome in monozygous twins, caused by a previously not described heterozygous mutation c.462C> G: p.I154M in the SOX10 gene in the absence of sensorineural hearing loss. The mutation was inherited from a father who has only isolated anosmia in the phenotype. This mutation was identified during full exome sequencing. This unique observation for Russia shows on the one hand expediency to check SOX10 sequence in addition to the other factors of neuronal migration and differentiation and, on the other hand, the prospect of full exome sequencing in a group of patients with undifferentiated iHH.

[Congenital adrenal hyperplasia due to 11ß-hydroxylase deficiency: late diagnosis and gender reassignment in a two-year-old child].

11ß-hydroxylase deficiency is a rare autosomal recessive disorder due to impaired steroidogenesis in the adrenal cortex caused by pathogenic mutations in the CYP11B1 gene. The main clinical manifestations are determined by a deficiency of cortisol, ACTH hyperproduction, excessive androgens secretion and the accumulation of 11-deoxycorticosterone, which leads to the development of arterial hypertension. In the diagnostic search, it is important to take into account the ethnicity of the patient, since the frequency of the disease and the prevalence of mutations differ between ethnic groups. The article presents a clinical case of 11ß-hydroxylase deficiency as the result of compound heterozygous mutations in the CYP11B1 gene in a patient of Turkic origin. This case shows the clinical manifestations and the development of complications of 11ß-hydroxylase deficiency, the stages of differential diagnosis of patients with 21-hydroxylase deficiency.

[CDC73 mutations in young patients with primary hyperparathyroidism: A description of two clinical cases]. / Mutatsii v gene CDC73 u molodykh patsientok s pervichnym giperparatireozom (opisanie dvukh klinicheskikh sluchaev).

The article describes two clinical cases of severe primary hyperparathyroidism (PHPT) caused by parathyroid carcinoma in young female patients who underwent molecular genetic testing to rule out the hereditary forms of PHPT. In both patients, heterozygous germline nonsense mutations of tumor suppressor gene CDC73 encoding parafibromin (p.R91X and p.Q166X) were identified using next-generation sequencing with Ion Torrent Personal Genome Machine (Thermo Fisher Scientific - Life Technologies, USA). It is the first description of CDC73 mutations in Russia, one of the mutations is described for the first time in the world. Identification of germline mutations in the CDC73 gene in patients with PHPT necessitates regular lifelong screening for other manifestations of hyperparathyroidism-jaw tumor syndrome (HPT-JT), PHPT recurrence due to parathyroid carcinoma as well, and identification of mutation carriers among first-degree relatives.

[Familial partial lipodystrophy (Dunnigan syndrome) due to LMNA gene mutation: The first description of its clinical case in Russia].

Hereditary lipodystrophies (HLD) are a heterogeneous group of rare diseases characterized by a complete or partial loss of subcutaneous fat and by the development of metabolic disturbances: diabetes mellitus with obvious insulin resistance and acanthosis nigricans, dyslipidemia, hepatic steatosis, hypertension, and polycystic ovary syndrome. The laminopathy variant familial partial lipodystrophy type 2 or Dunnigan syndrome (FPLD2) is the most common cause of partial LD. The paper describes a family (3 clinical cases) with FPLD2 caused by heterozygous R482W missense mutations in the gene encoding the protein lamin A/C (LMNA; 150330). This observation demonstrates that specialists should be more aware of this disease and make a timely diagnose in cases of concurrent severe metabolic disturbances at a young age, which contributes to more effective treatment of patients and to medical genetic counseling of their families.

[Molecular genetic verification of isolated mineralocorticoid deficiency due to aldosterone synthase deficiency].

Isolated mineralocorticoid deficiency is a rare hereditary autosomal recessive disorder that is characterized by salt wasting and that has the severest manifestations in infants. This paper is the first in the Russian literature to describe cases of isolated aldosterone deficiency. In both cases, the patients were monitored and treated for misdiagnosed congenital adrenal hyperplasia; however, the permanently low level of 17-hydroxyprogesterone could put in doubt the diagnosis and suspect isolated mineralocorticoid deficiency, by keeping in mind a history of salt wasting. By using the presented cases as an example, the authors give an algorithm for the examination and differential diagnosis of this condition and other diseases that have the similar clinical picture. Aldosterone synthase deficiency in patients was verified by molecular genetic studies - there were mutations in the CYP112 gene.

[Familial type of nephrogenic diabetes insipidus with partially preserved renal concentration function, which is caused by homozygous D150E mutation in the aquaporin-2 (AQP-2) gene].

Nephrogenic diabetes Insipidus (NDI) is a heterogeneous disease in the etiopathogenesis of which acquired and congenital factors may be of importance. The authors describe a case of the familial type of NDI caused by aquaporin-2 deficiency. A 9-year-old boy and a 2-year-old girl, bom to closely related parents, were observed to have polydipsia and polyuria in the first months of life. A water deprivation test carried out in both children indicated the capacity of partially concentrate urine (urinary osmolality being increased from 160 to 614 m Osmol/kg in the boy and from 247 to 487 m Osmol/kg in the girl). At the same time, plasma osmolality changed from 229 to 252 m Osmol/kg in the boy and from 270 to 283 mOsmol/kg In the girl. Urinary osmolality remained unchanged after oral administration of minirin, 10: The dDAVP test using intranasalminirin, 20showed the elevated plasma concentrations of clotting factors (factor VIII and von Willebrand factor). Molecular genetic analysis of the AQP2 gene in both children revealed homozygous missense mutation in exon 2, leading to the substitution of aspartic acid for glutamic acid in position 150 (D150E). Their mother without clinical signs of NDI was found to be this mutation heterozygous. Therefore, D150E mutation in the AQP2 gene was detected in 2 siblings with NDI and partially preserved renal concentration function.

[Lipoid adrenal hyperplasia caused by earlier unknown 21STAR gene mutations].

Lipoid adrenal hyperplasia (LAH) is a most severe type of congenital adrenal cortical dysfunction (CACD). In this type of CACD, there is defect in the conversion of cholesterol to pregnenolone, as a consequence the production of all steroid hormones was impaired in both the adrenals and gonads. Defects of the STAR gene encoding for a steroidogenic acute regulatory (StAR) protein underlie the disease in most cases. Until the present time, there have been no reports on cases of LAH in the Russian literature. The diagnosis of LAH was established by the authors in three genetic girls aged 2.3 years, 6 and 7 months who had a normal structure of the external genitalia and in whom the disease was marked by manifestations of primary hypoadrenocorticism at the age of 21, 2, and 10 days, respectively. A hormonal study failed to show elevated levels of Cortisol and 17-hydroxyprogesterone in response to adrenocorticotropic hormone stimulation. A molecular genetic study revealed the following STAR gene defects: P129AC/W250X, IVS5-1G, and W147X, respectively. Р129ЛС, IVSS, and W147X mutations have not been earlier described. The data of the observation emphasizes the need of including LAH into the algorithm of differential diagnosis of CACD in children with the normal female structure of the external genitalia. The molecular genetic analysis should be prominent in diagnosing LAH, by taking into account the lack of hormonal markers of the disease.

[New mutation in the CYP17 gene: description of a case].

Deficiency of 17α-hydroxylase is a rare variant of congenital adrenal cortical dysfunction. The defect was first described by E. Biglieri et al. in 1966 in patients with sexual infantilism, pronounced excess mineralocorticoids with salt retention and arterial hypertension. Currently, several variants of the nonclassical course of the disease are described (with an increased level of aldosterone and without the development of hypertension and hypokalemia), the pathophysiological mechanism of which could not be explained. Cases of isolated deficiency of 17,20-lyase activity associated with mutations of R347H and R358Q in the CYP17 gene are also described. Here is the observation of a patient with a new mutation in the CYP17 gene with 17α-hydroxylase/17,20-lyase deficiency.