Clinical and genetic characteristics of combined pituitary hormone deficiency caused by aberrations in the PROP1 gene
Background: One of the most common causes of congenital hypopituitarism is the occurrence of inactivating variant aberrations in the PROP1 gene. Encoding the transcription factor of the same name, PROP1 is a key regulator of the differentiation of pluripotent cells of the anterior pituitary gland into individual cell lines with characteristic secretory profiles. Homozygous and compound heterozygous variants of the PROP1 gene lead to the development of combined pituitary hormone deficiency, characterized by deficiency of somatotropic hormone (STH), thyroid-stimulating hormone (TSH), prolactin (PRL), and gonadotropic hormones. Deficiency of adrenocorticotropic hormone (ACTH) is a more variable symptom, in rare cases it can develop in childhood, more often in adolescence and older age, or it can be absent throughout the patient’s life. In 1998, cDNA of the human PROP1 gene was cloned by P. Duquesnoy et al. In the same year, O.V. Fofanova, together with S. Yamashita and other Japanese scientists were among the first to identify defects in the PROP1 genes in patients with multiple pituitary hormone deficiency. More and more data concerning the study of this problem are appearing in the foreign literature. In the domestic literature, there are descriptions of a small number of groups of patients with defects in the PROP1 gene. This work is aimed at expanding the understanding of the etiology, pathogenesis and characteristics of this rare disease.E.N. Raykina, M.S. Pankratova, E.V. Nagaeva, A.A. Kolodkina, T.Yu. Shiryaeva, O.A. Chikulaeva, O.B. Bezlepkina, V.A. Peterkova
Objective. Clinical, hormonal and molecular genetic characteristics of cases of monogenic hypopituitarism associated with variants in the PROP1 gene.
Materials and methods: A single-center, non-interventional, cross-sectional, non-comparative study was conducted, which included 54 patients with hypopituitarism associated with a variant substitution in the PROP1 gene. All patients underwent a comprehensive examination, including laboratory and instrumental diagnostic methods and NGS (next-generation sequencing).
Results: 54 children (30 girls, 24 boys) with variant substitutions in the PROP1 gene were examined. The frequency of variant substitutions in the PROP1 gene among children with monogenic hypopituitarism in the Russian population was 44% (95% CI: 34.5–52.7). All identified variants in the PROP1 gene were previously described in the world literature as pathogenic. The most common defect was the compound heterozygous variant c.301_302del/c.150del – detected in 23 (42.5%) cases. The age at the time of hypopituitarism diagnosis was 4.5 (3.0–5.6) years. All children had growth hormone deficiency and secondary hypothyroidism. In a smaller number of cases, hypopituitarism included corticotropic hormone deficiency (40.7%) and hypoprolactinemia (16.6%). Secondary hypogonadism was diagnosed in all children who reached puberty (n=17). According to the results of magnetic resonance imaging of the brain, changes typical for a defect in the PROP1 gene (hyperplasia of the pituitary gland and total changes in the structure of the pituitary gland) were detected in 46% of cases, pituitary hypoplasia – in 26% of cases.
Conclusion: The largest domestic study on the frequency of PROP1-associated hypopituitarism was conducted. In patients with the same aberration, the age and sequence of manifestation of tropic deficiencies can vary significantly. The high probability of developing secondary hypocorticism in this genetic defect postulates the extreme importance of monitoring patients throughout their lives, including the need for regular monitoring of serum cortisol levels.
Keywords
congenital hypopituitarism
monogenic hypopituitarism
somatotropic insufficiency
hypothyroidism
hypocorticism
About the Authors
Elizaveta N. Raykina, clinical postgraduate student, National Medical Research Center of Endocrinology, Moscow, Russia; dr.raykina@mail.ru (corresponding author)Maria S. Pankratova, Cand. Sci. (Med.), Doctor of the Highest Qualification Category, Associate Professor at the Department of Pediatric Endocrinology-Diabetology, Leading Researcher at the Department of Endocrine Tumors, National Medical Research Center of Endocrinology, Moscow, Russia; ORCID: https://orcid.org/0000-0003-3396-8678; SPIN-code: 3770-4452
Elena V. Nagaeva, Dr. Sci. (Med.), Professor at the Department of Pediatric Endocrinology-Diabetology, Head of the Department of Thyroidology, Somatic and Reproductive Health, Deputy Chief Physician for Pediatric Endocrinology, National Medical Research Center of Endocrinology, Moscow, Russia; ORCID: https://orcid.org/0000-0001-6429-7198, eLibrary SPIN: 4878-7810
Anna A. Kolodkina, Cand. Sci. (Med.), Associate Professor at the Department of Pediatric Endocrinology-Diabetology, Head of the Department of Hereditary Diseases and Endocrinopathy of Early Childhood, National Medical Research Center of Endocrinology, Moscow, Russia; ORCID:
https://orcid.org/0000-0001-7736-5372, SPIN-code: 6705-6630
Tatyana Yu. Shiryaeva, Cand. Sci. (Med.), Doctor of the Highest Qualification Category, Leading Researcher at the Department of Thyroidology, Somatic and Reproductive Health, National Medical Research Center of Endocrinology, Moscow, Russia; ORCID: https://orcid.org/0000-0002-2604-1703, SPIN-code: 1322-0042
Olga A. Chikulaeva, Cand. Sci. (Med.), Associate Professor at the Department of Pediatric Endocrinology-Diabetology, Doctor of the Highest Qualification Category, Leading Researcher at the Department of Thyroidology, Somatic and Reproductive Health, National Medical Research Center of Endocrinology; Head of the Department for Organization of Medical Care in the Profile of Endocrinology/Pediatric Endocrinology in the Constituent Entities of the Russian Federation of the Coordination Council, Moscow, Russia; ORCID: https://orcid.org/0000-0002-4743-4661
Olga B. Bezlepkina, Dr. Sci. (Med.), Professor, Deputy Director of the Center– Director of the Institute of Pediatric Endocrinology, National Medical Research Center of Endocrinology, Moscow, Russia; ORCID: https://orcid.org/0000-0001-9621-5732, SPIN-code: 3884-0945
Valentina A. Peterkova, Dr. Sci. (Med.), Professor, Academician of the Russian Academy of Sciences, Chief Pediatric Endocrinologist of the Ministry of Health of Russia, Head of the Department of Pediatric Endocrinology-Diabetology, Scientific Director of the Institute of Pediatric Endocrinology, National Medical Research Center of Endocrinology, Moscow, Russia; ORCID: https://orcid.org/0000-0002-5507-4627, SPIN-code: 4009-2463