[Preclinical diagnostics of von Hippel-Lindau syndrome in a child]

The description of the child aged 5 months with the von Hippel-Lindau syndrome without any manifestations of this syndrome is presented. The reason for the molecular genetic examination was the presence of cases of this syndrome in the family (mother and sister). The heterozygous variant c.355T>C p.F119L was found in the VHL gene. An objective examination revealed no pathology. A comprehensive laboratory and instrumental examination aimed at searching for components of the von Hippel-Lindau syndrome, including a blood test for metanephrines and normetanephrines, ultrasound of the abdominal organs, examination of the fundus, also did not reveal any abnormalities. Given the results of molecular genetic diagnosis, the child remains under observation and will undergo regular examinations to identify components of the von Hippel-Lindau syndrome, including blood/urine tests for normetanephrines.

[Primary Generalized Glucocorticoid Resistance: a case report]

Primary glucocorticoid resistance (OMIM 615962) is a rare endocrinologic condition caused by resistance of the human glucocorticoid receptor (hGR) to glucocorticoids (GR) and characterised by general or partial insensitivity of target organs to GK. Compensatory activation of hypothalamic-pituitary-andrenal axis results in development of a various pathological conditions caused by overstimulation of adrenal glands. Clinical spectrum may range from asymptomatic cases to severe cases of mineralocorticoid and/or androgen excess. At present time, primary generalized glucocorticoid resistance has been exclusively associated with defects in the NR3C1 gene. Here, we present a case report of an adolescent patient with clinical presentation of glucocorticoid resistance confirmed by detailed endocrinologic evaluation but no confirmed mutations in the NR3C1 gene.

[Intestinal ganglioneuromatosis as an early extra-endocrine manifestation of type 2B multiple endocrine neoplasia]

Multiple endocrine neoplasia type 2B (MEN 2B) is a rare variant of hereditary tumor syndromes caused by germinal mutations in the proto-oncogene RET. One of the components of the syndrome is multiple neurinomas, the early detection of  which is not always given due attention. We present a description of the case of MEN 2B, manifested in the first months of life by intestinal ganglioneuromatosis. The disease presented with chronic constipation, including episodes of intestinal obstruction that required repeated surgical interventions. MEN 2B was suspected at the age of 15. At the time of diagnosis, an increase in serum calcitonin levels was noted (1041 pg/ml, norm <9.5 pg/ml), and a node in the thyroid gland was also determined (1,3*1,0*1,2 see, TIRADS 5), subsequently verified as a neoplasm of C-cells. By DNA analysis, a pathogenic variant p.Met918Thr, typical for MEN2 B, was detected in the RET gene. No signs of pheochromocytoma were found at the time of investigation. The patient underwent a thyroidectomy with lymphadenectomy. The difficulties of early diagnosis of sporadic cases of MEN 2B due to the nonspecificity of gastrointestinal manifestations of the disease are discussed.

[Morphological characteristics of pituitary adenomas in the phenocopy of multiple endocrine neoplasia type 1]

BACKGROUND

Multiple endocrine neoplasia type 1 (MEN 1) is a rare autosomal dominant disorder caused by mutations in the MEN1 gene, which encodes the menin protein. If a patient has the MEN 1 phenotype in the absence of mutations in the MEN1 gene, the condition is classified as a phenocopy of this syndrome. Although significant progress has been made in understanding the function of menin, its role in the oncogenesis of the endocrine glands is still being elucidated. Due to its key role in physiological and pathological processes, the assessment of the menin expression can provide valuable information.

AIM

to determine whether there are any differences in the expression of menin in the pituitary adenomas (PA) in patients with phenocopy of MEN 1 (phMEN 1) and genetically confirmed MEN 1 (gMEN 1) compared with their sporadic forms.

MATERIALS AND METHODS

immunohistochemical assessment of the menin expression was carried out in PA of patients with gMEN 1, phMEN 1 and sporadic acromegaly (SA), surgically treated in 2008-2020. IHC was performed using antibodies to menin, PRL, GH, ACTH, FSH, TSH, Pit-1, T-box, ERA on previously prepared histological section.

RESULTS

The study included 35 samples of PA: gMEN 1 - 9 samples, phMEN 1 - 12 (somatotropinomas + PHPT); CA - 14  samples. The patients were comparable by gender, adenoma size, and drug intake. The gMEN  1 group differed from phMEN 1 and SA by age (p = 0.0005). In patients with gMEN 1, the expression of menin varied from no staining (5/9) to intense cytoplasm staining. Cytoplasmic expression of menin was mainly present (11/12) in the phMEN 1. In the SA group, there was no staining in 1 case; nuclear expression was detected in 6/14 cases. The phMEN  1 group showed significantly higher cytoplasmic expression of menin than the gMEN  1 group (p = 0.006). The gMEN 1 group also differed from the SA group (p = 0.012). There were no statistically significant differences between the phMEN 1 and SA groups (p = 0.049).

CONCLUSION

It was revealed that the menin expression, in general, is retained in phMEN 1 and SA groups, although with different localization in the cell structure (nucleus and / or cytoplasm). At the same time, the expression of menin varies greatly in patients with gMEN 1. According to the data obtained, it can be assumed that the pathogenesis of PA in phMEN 1 and SA may have similarities; however, there could be factors contributing to the appearance of several tumors of the endocrine glands in one person with phMEN 1. To understand this process, it is necessary to further study the genes associated with MEN 1, epigenetic factors, signaling pathways in which menin is involved.

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

11β-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 11β-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 11β-hydroxylase deficiency, the stages of differential diagnosis of patients with 21-hydroxylase deficiency.

[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&gt; 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.