Literature Cases Summarized Based on Their Polysomnographic Findings in Rett Syndrome.

Xin-Yan Zhang,Karen Spruyt

doi:10.3390/ijerph19063422

Abstract

Rett syndrome (RTT) is a severe and rare neurodevelopmental disorder affecting mostly girls. In RTT, an impaired sleep pattern is a supportive criterion for the diagnosis, yet little is known regarding the sleep structure and sleep respiratory events. Aiming to delineate sleep by aggregating RTT case (series) data from published polysomnographic studies, seventy-four RTT cases were collected from eleven studies up until 6 February 2022 (PROSPERO: CRD 42020198099). We compared the polysomnographic data within RTT stratifications and to a typically developing population. MECP2 cases demonstrated shortened total sleep time (TST) with increased stage N3 and decreased REM sleep. In cases with CDKL5 mutations, TST was longer and they spent more time in stage N1 but less in stage N3 than those cases affected by MECP2 mutations and a typically developing population. Sleep-disordered breathing was confirmed by the abnormal apnea/hypopnea index of 11.92 ± 23.67/h TST in these aggregated cases. No association of sleep structure with chronological age was found. In RTT, the sleep macrostructure of MECP2 versus CDKL5 cases showed differences, particularly regarding sleep stage N3. A severe REM sleep propensity reduction was found. Aberrant sleep cycling, possibly characterized by a poor REM ‘on switch’ and preponderance in slow and high-voltage sleep, is proposed.

Highlights

Public Health 2022, 19, 3422. https://Rett syndrome (RTT, OMIM # 312750) is a rare neurodevelopmental disorder predominantly occurring in females [1]
In cases with cyclin-dependent kinase-like 5 (CDKL5) mutations, total sleep time (TST) was longer and they spent more time in stage N1 but less in stage N3 than those cases affected by methyl-CpG-binding protein-2 (MECP2) mutations and a typically developing population
We found no significant association of the polysomnographic chronoin the stratum was negatively correlated with age (n =in12,the logical age at PSG in either the RTT total group or any strata (Figure 3)

Summary

Introduction

Rett syndrome (RTT, OMIM # 312750) is a rare neurodevelopmental disorder predominantly occurring in females [1]. Mutations in genes such as methyl-CpG-binding protein-2. Abnormal characteristics of RTT usually become visible after months of “normal” development followed by profound regression, such as loss of functional hand skills, spoken language and mobility, as well as the presence of stereotypical hand movements, cognitive disabilities and gait dyspraxia [1,6]. Classic and variant phenotypic RTT are defined by the (partial) presence of the abovementioned clinical features [1]. Cases with RTT are described by the course of their traits, i.e., early-onset stagnation

Objectives

Methods

Discussion

Conclusion