Diagnostic features of Prader–Willi syndrome in the neonatal period
Authors:   N.I.Pirogov Russian National Research Medical University, Moscow, Russian Federation, Shakirova A.A. , Kantutis S.S. ,   N.I.Pirogov Russian National Research Medical University, Moscow, Russian Federation, Pravoslavnaya O.V. ,   N.I.Pirogov Russian National Research Medical University, Moscow, Russian Federation, Shumilov P.V. ,   N.I.Pirogov Russian National Research Medical University, Moscow, Russian Federation, Demyanova T.G. ,   N.I.Pirogov Russian National Research Medical University, Moscow, Russian Federation, Sarkisyan H.A. ,   N.I.Pirogov Russian National Research Medical University, Moscow, Russian Federation, Chugunova O.L. ,   N.I.Pirogov Russian National Research Medical University, Moscow, Russian Federation,   N.F.Filatov Children’s City Clinical Hospital, Moscow, Russian Federation, Cherkasova S.V. ,   N.I.Pirogov Russian National Research Medical University, Moscow, Russian Federation,   N.F.Filatov Children’s City Clinical Hospital, Moscow, Russian Federation, Chubarova A.I. ,   N.I.Pirogov Russian National Research Medical University, Moscow, Russian Federation,   N.F.Filatov Children’s City Clinical Hospital, Moscow, Russian Federation
Published: February 2024

Objective. To demonstrate the clinical features of Prader–Willi syndrome (PWS) in the neonatal period, to assess the impact of perinatal factors on the development and severity of PWS, and to compare the data obtained with literary sources. Patients and methods. This cross-sectional open-label retrospective study was conducted between 2022 and 2023. It included 5 neonates with severe hypotonia and subsequently confirmed PWS. Anamnestic, anthropometric, age- and sex-related characteristics of children with PWS and anamnestic data of their mothers, as well as clinical manifestations of PWS were investigated. Results. Most of the children with PWS were born prematurely, with a mean birth weight of 2512.0 ± 549.5 g, height of 48.2 ± 5.1 cm, and head circumference of 32.9 ± 2.5 cm, which is below the standard values for preterm infants. The mean Apgar score was 5.8 ± 2.8/7.2 ± 1.9. Three out of five children were not appropriate for gestational age, having low values according to the INTERGROWTH-21st standards. Children were born to mothers aged 35 ± 5 years, and 3 (60%) out of 5 women had an aggravated somatic and/or obstetric and gynecological history. Evaluation of clinical manifestations of PWS revealed post-hypoxic injury of the central nervous system (CNS) (100%), respiratory disorders (100%), infectious toxicosis and intrauterine pneumonia (80%). Objective examination revealed hypotonia, hyporeflexia, reduced motor function in all patients, and 80% of children had poor sucking reflex. The most common phenotypic features were high forehead, almondshaped eyes, dolichocephaly, narrow temporal bones, thin upper lip, down-turned corners of the mouth; orbital hypertelorism, acromicria, and hypogonadism were observed less frequently. Conclusion. Early diagnosis of PWS is possible with a comprehensive differential diagnosis in children with the “floppy baby syndrome”. Special attention should be paid to children with intrauterine growth restriction, typical stigmas of dysembryogenesis, respiratory disorders, and hypoxic CNS injury. Genetic counseling and karyotyping should be performed as early as possible in all newborns with suspected PWS to prevent the development of complications. Key words: Prader–Willi syndrome, floppy baby syndrome, stigmas of dysembryogenesis, hypotonia, hyporeflexia, poor sucking reflex, feeding disorders, developmental delay, hypogonadism