Justification. Obesity is a multifactorial disorder that has become one of the most serious and widespread pediatric problems, with an incidence ranging from 1.7% to 6.3 %. Genetically determined forms are difficult to diagnose and distinguish from each other, with Prader-Willi syndrome being the most common of these disorders. Accurate differentiation from other syndromic forms of obesity is essential and requires the use of genetic diagnostic methods. We present the first description in Russia of a girl initially observed with suspected Prader–Willi syndrome in whom whole-genome sequencing revealed a 1p36 deletion. The girl had been followed by a neurologist since the age of 7 months because of muscular hypotonia. At the age of 2 years, she was evaluated for a suspected syndromic disorder (hypotonia, obesity, and developmental delay) and was hospitalized at the Institute of Pediatrics of PIMU. Based on the results of further clinical evaluation, Prader–Willi syndrome was suspected; however, methylation analysis of the SNRPN gene did not confirm the diagnosis. Subsequent whole-genome sequencing identified a 1p36 deletion, a syndrome with a phenotype that may resemble Prader–Willi syndrome. This case highlights the challenges of the differential diagnosis of syndromic obesity in children and provides a detailed comparison of these nosological entities.
Challenges in the differential diagnosis of 1p36 deletion syndrome and Prader–Willi syndrome
https://doi.org/10.52485/19986173_2026_1_200
Abstract
Supporting agencies: The study had no financial support
About the Authors
N. A. Chernevskay
“Privolzhsky Research Medical University” of the Ministry of Health of the Russian Federation
Russian Federation
Russian Federation
Assistant
Department of Pediatrics named after F.D. Agafonov
603005; 10/1 Minin and Pozharsky Square; Nizhny Novgorod
O. D. Elshina
“Privolzhsky Research Medical University” of the Ministry of Health of the Russian Federation
Russian Federation
Russian Federation
Head of the Department, Neurologist
603005; 10/1 Minin and Pozharsky Square; Nizhny Novgorod
E. N. Fedulova
“Privolzhsky Research Medical University” of the Ministry of Health of the Russian Federation
Russian Federation
Russian Federation
Doctor of Medical Sciences, Associate Professor, Head of the Department
Department of Pediatrics named after F.D. Agafonov; Pediatric Department
603005; 10/1 Minin and Pozharsky Square; Nizhny Novgorod
D. K. Chernevsky
“Privolzhsky Research Medical University” of the Ministry of Health of the Russian Federation
Russian Federation
Russian Federation
Candidate of Medical Sciences, Medical Geneticist
Consultative and Diagnostic Department
603005; 10/1 Minin and Pozharsky Square; Nizhny Novgorod
D. B. Pudalov
“Privolzhsky Research Medical University” of the Ministry of Health of the Russian Federation
Russian Federation
Russian Federation
3rd-year student
Faculty of Pediatrics
603005; 10/1 Minin and Pozharsky Square; Nizhny Novgorod
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Review
For citations:
Chernevskay N.A., Elshina O.D., Fedulova E.N., Chernevsky D.K., Pudalov D.B. Challenges in the differential diagnosis of 1p36 deletion syndrome and Prader–Willi syndrome. Transbaikalian Medical Bulletin. 2026;(1):200-208. (In Russ.) https://doi.org/10.52485/19986173_2026_1_200
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