Sleep in Children With Pallister Killian Syndrome: A Prospective Clinical and Videopolysomnographic Study.

Federica Provini,Lucio Giordano,Veronica Di Pisa,Anna Fetta,Dario Pruna,Emilia Ricci,Luca Soliani,Sara Ubertiello,Duccio Maria Cordelli,Greta Mainieri,Giacomo Sperti,Maria Margherita Mancardi,Alessandro Rocca,Martina Ruscelli,Aglaia Vignoli

doi:10.3389/fneur.2021.796828

Abstract

Objectives: Pallister-Killian syndrome (PKS) is a rare genetic disorder with multi-organ involvement caused by mosaic tetrasomy of chromosome 12p. Although many caregivers report the presence of impaired sleep in their children, there are no clear data in the literature on this issue and no systematic study has ever been performed. With this study, we aimed to characterize the features of sleep in Pallister-Killian syndrome and identify the possible influence of clinical and demographic features. Moreover, our aim was to verify the effectiveness of conventional screening questionnaires in this particular group of patients.Methods: We prospectively enrolled 14 patients aged 1–17 years in collaboration with PKS Kids Italia ONLUS. The Sleep Disturbance Scale for Children (SDSC) questionnaire was administered to caregivers. Then, video polysomnography (VPSG) of at least 24 h was performed and results were compared with a same-aged control group.Results: A total of 92% of patients had abnormal SDSC scores, extremely high in the “disorder of initiating and maintaining sleep” (DIMS) and “sleep breathing disorders” (SBD) subscales. VPSG showed a significantly impaired macrostructure in PKS patients, with a higher Arousal Index (p < 0.00001) and percentage of time spent in N3 (p < 0.00001), and reduced Sleep Efficiency (p = 0.0006). After dividing both PKS and controls into two groups based on median age, some peculiarities emerged: the younger group had higher Awakenings Index (p = 0.0207) and percentage of time spent in N1 (p = 0.015) while the older group showed higher time in bed (TIB) (p = 0.0485), compared with controls. Due to poor compliance, the Apnea-Hypopnea Index (AHI) was evaluated only for 10 PKS children, being significantly increased (p = 0.0427) compared with controls. SBD subscale scores in SDSC were significantly related to AHI values in VPSG (p = 0.0099).Conclusions: This study constitutes the first attempt to describe the sleep pattern in PKS. Despite small numbers due to the rarity of the syndrome, our VPSG results confirm the high prevalence of sleep disorders (SDs) in these patients. It is therefore essential to investigate and treat them. The SDSC scale is a good screening tool for early detection also in these patients, with particular sensitivity in detecting breathing disorders.

Highlights

Pallister-Killian syndrome (PKS) or 12p tetrasomy is a tissuelimited mosaic aneuploidy, in which most cases are due to the presence of a supernumerary 12p isochromosome [1]
VPSG revealed a high prevalence of sleep disorders (SDs) and the presence of pathological sleep macrostructure, with abnormalities in most of the parameters analyzed, especially a reduction in sleep efficiency index (SEI) and an increase in the arousal index (AI) and the percentage of N3
There may be an age-dependent evolution of sleep architecture, with nocturnal awakenings and increased proportion of N1 in younger patients and increased time spent in bed in older patients

Summary

Introduction

Pallister-Killian syndrome (PKS) or 12p tetrasomy is a tissuelimited mosaic aneuploidy, in which most cases are due to the presence of a supernumerary 12p isochromosome [1]. The phenotypic spectrum is broad, characterized by facial dimorphism, skin pigmentation differences (hypopigmentation/hyperpigmentation), multiple congenital anomalies (including cerebral malformation), hypotonia, epilepsy, neuromotor delay, and intellectual disability (ID) [2]. The phenotype is variable, most of the patients have a severe neurological impairment that highly impacts on their life [3]. Sleep is frequently impaired in children with neurodevelopmental disorders (NDDs) and multiple disabilities [4]. Differently from typically developing (TD) children, the ones in NDDs tend to be chronic, lasting into adolescence or adulthood [5]. A recent meta-analysis investigated the prevalence of sleep disorders (SDs) in 19 rare genetic syndromes (GSs) and found an average higher frequency than in TD children, with extreme variability in the type of sleep disorder across syndromes [6]

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