Seizure variables and their relationship to genotype and functional abilities in the CDKL5 disorder.

OBJECTIVE: To investigate seizure outcomes and their relationships to genotype and functional abilities in individuals with the cyclin-dependent kinase-like-5 (CDKL5) disorder. METHODS: Using the International CDKL5 Disorder Database, we identified 172 cases with a pathogenic CDKL5 mutation. We categorized individual mutations into 4 groups based on predicted structural and functional consequences. Negative binomial regression was used to model the linear association between current seizure rate and mutation group, current level of assistance required to walk 10 steps, and the highest level of expressive communication used to convey refusal or request. RESULTS: All but 3 (169/172) patients had a history of epilepsy. The median age at seizure onset was 6 weeks (range 1 week-1.5 years) and the median seizure rate at ascertainment was 2 per day (range 0-20 per day). After adjusting for walking ability and confounders including use or otherwise of polytherapy, seizure rate was lower in those with truncating mutations between aa172 and aa781 compared to those with no functional protein (incidence rate ratio [IRR] 0.57; 95% confidence interval [CI] 0.35-0.93). Ability to walk and use of spoken language were associated with lower rates of current seizures when compared to those with the least ability after adjusting for genotype (walking: IRR 0.62; 95% CI 0.39-0.99, communication: IRR 0.48; 95% CI 0.23-1.02). At a median age at questionnaire completion of 5 years, those previously treated with corticosteroids had more frequent seizures than those who have never been treated, whether or not there was a history of infantile spasms. CONCLUSIONS: Epilepsy is pervasive but not mandatory for the CDKL5 disorder. Genotype and functional abilities were related to seizure frequency, which appears refractory to antiepileptic drugs.

Functional abilities in children and adults with the CDKL5 disorder.

Functional abilities in the CDKL5 disorder have been described as severely impaired, yet some individuals are able to run and use phrases for speech. Our study investigated gross motor, hand function, and expressive communication abilities in individuals with the CDKL5 disorder. Data for 108 females and 16 males registered with the International CDKL5 disorder database and with a pathogenic CDKL5 mutation were analyzed. Relationships between functional abilities, age, genotype, and gender were analyzed using regression models. Over half of the females could sit on the floor and nearly a quarter could walk 10 steps. Fewer males could complete these tasks although one boy was able to sit, walk, and run. Most females and few males were able to pick up a large object. Females mostly used gestures to communicate while males mostly used other forms of non-verbal communication. Compared to those with no functional CDKL5 protein, individuals with truncating variants after aa 781 were more likely to be able to stand (OR 5.7, 95%CI 1.2, 26.6) or walk independently (4.3, 95%CI 0.9, 20.5), and use more advanced communication methods such as words (OR 6.1, 95%CI 1.5-24.2). Although abilities were markedly impaired for the majority with the CDKL5 disorder, some females and a few males had better functional abilities. This variability may be related to underlying gene variants, with females with a late truncating variant having better levels of ability than those with no functional protein. © 2016 Wiley Periodicals, Inc.

There is variability in the attainment of developmental milestones in the CDKL5 disorder.

BACKGROUND: Individuals with the CDKL5 disorder have been described as having severely impaired development. A few individuals have been reported having attained more milestones including walking and running. Our aim was to investigate variation in attainment of developmental milestones and associations with underlying genotype. METHODS: Data was sourced from the International CDKL5 Disorder Database, and individuals were included if they had a pathogenic or probably pathogenic CDKL5 mutation and information on early development. Kaplan-Meier time-to-event analyses investigated the occurrence of developmental milestones. Mutations were grouped by their structural/functional consequence, and Cox regression was used to investigate the relationship between genotype and milestone attainment. RESULTS: The study included 109 females and 18 males. By 5 years of age, only 75% of the females had attained independent sitting and 25% independent walking whilst a quarter of the males could sit independently by 1 year 3 months. Only one boy could walk independently. No clear relationship between mutation group and milestone attainment was present, although females with a late truncating mutation attained the most milestones. CONCLUSION: Attainment of developmental milestones is severely impaired in the CDKL5 disorder, with the majority who did attain skills attaining them at a late age. It appears as though males are more severely impaired than the females. Larger studies are needed to further investigate the role of genotype on clinical variability.

The CDKL5 disorder is an independent clinical entity associated with early-onset encephalopathy.

The clinical understanding of the CDKL5 disorder remains limited, with most information being derived from small patient groups seen at individual centres. This study uses a large international data collection to describe the clinical profile of the CDKL5 disorder and compare with Rett syndrome (RTT). Information on individuals with cyclin-dependent kinase-like 5 (CDKL5) mutations (n=86) and females with MECP2 mutations (n=920) was sourced from the InterRett database. Available photographs of CDKL5 patients were examined for dysmorphic features. The proportion of CDKL5 patients meeting the recent Neul criteria for atypical RTT was determined. Logistic regression and time-to-event analyses were used to compare the occurrence of Rett-like features in those with MECP2 and CDKL5 mutations. Most individuals with CDKL5 mutations had severe developmental delay from birth, seizure onset before the age of 3 months and similar non-dysmorphic features. Less than one-quarter met the criteria for early-onset seizure variant RTT. Seizures and sleep disturbances were more common than in those with MECP2 mutations whereas features of regression and spinal curvature were less common. The CDKL5 disorder presents with a distinct clinical profile and a subtle facial, limb and hand phenotype that may assist in differentiation from other early-onset encephalopathies. Although mutations in the CDKL5 gene have been described in association with the early-onset variant of RTT, in our study the majority did not meet these criteria. Therefore, the CDKL5 disorder should be considered separate to RTT, rather than another variant.

Prolonged use of benzodiazepines is associated with childhood trauma in opioid-maintained patients.

BACKGROUND: Benzodiazepine (BZD) misuse in opioid-maintained patients is widespread and has been related to poorer treatment success. Associated factors, in particular, traumatic childhood experiences, have not been investigated extensively. METHODS: Cross-sectional survey including the childhood trauma questionnaire (CTQ) and clinical data among 193 patients prescribed oral opioids or injectable diacetylmorphine for opioid dependence. RESULTS: BZD use was prevalent (61%) and the burden of childhood traumatic experiences was high with 67% reporting at least one trauma subscore of moderate-to-severe level. In univariate analysis, CTQ-subcategories "emotional abuse" (p<0.05), "emotional neglect" (p<0.01) and "physical neglect" (p<0.001) were significantly associated with prolonged BZD use. In multivariate analysis, prolonged BZD use was associated with categorized overall CTQ-scores (OR 1.5), HCV-seropositivity (OR 4.0), psychiatric family history (OR 2.3), and opioid dose (mg methadone equivalents, OR 1.010). CONCLUSIONS: Childhood traumatic experiences may be associated with prolonged BZD use in opioid-maintained patients and could pose an important starting-point for prevention.

Trends in the diagnosis of Rett syndrome in Australia.

Modifications to diagnostic criteria and introduction of genetic testing have likely affected the pattern and timing of Rett syndrome diagnosis. The trends in incidence and prevalence of Rett syndrome in Australia were examined; the cumulative risk of a female being diagnosed was determined; and the impact of changes to diagnostic criteria and availability of genetic testing on these frequencies was investigated. The population-based Australian Rett Syndrome Database was used to identify a total of 349 verified Rett syndrome females born 1976-2006 and diagnosed 1982-2008. The proportion of female cases born and diagnosed per year and the cumulative risk of a diagnosis were determined. The median age of Rett syndrome diagnosis decreased from 4.5 y if diagnosed before 2000 to 3.5 y if diagnosed after 1999. The cumulative risk of diagnosis had almost doubled by 32 y of age [1/8,905 or 11.23 per 100,000 person-years (95% CI, 10.03-12.45)] in comparison with 5 y of age [1/15,361 or 6.51 per 100,000 person-years (95% CI, 5.65-7.39)]. Earlier age of diagnosis may result in families experiencing less stress and emotional strain compared with those with delayed diagnosis.

Altered attainment of developmental milestones influences the age of diagnosis of rett syndrome.

The early developmental history prior to the manifestation of Rett syndrome features is of clinical interest. This study describes the attainment of gross developmental milestones and regression, and assesses the relationships between genotype and age at diagnosis. The Australian Rett Syndrome Database and International Rett Syndrome Phenotype Database were used to source a total of 293 confirmed female subjects. Most girls learned to sit, were able to babble or use words, and approximately half learned to walk. Altered milestone attainment was associated with earlier diagnosis. There was variation in the acquisition of milestones, the age of regression, and the age of diagnosis by genotype. Most parents expressed concerns about unusual behaviors or development during infancy, and a more subtle atypical development during infancy was reported for most girls. It is important for clinicians to be aware of variable early development in Rett syndrome and that timely genetic testing is not precluded on this account.

Atypical presentations and specific genotypes are associated with a delay in diagnosis in females with Rett syndrome.

There is often delay between onset of Rett syndrome symptoms and its diagnosis, possibly related to symptom presentation or socio-demographic factors. We hypothesized that girls with an atypical presentation or whose family had a lower socio-economic status would receive a later diagnosis. Female subjects with a confirmed diagnosis of Rett syndrome were sourced from the Australian Rett Syndrome and InterRett Databases. Variables analyzed included timing and development of symptoms; MECP2 mutation type; parental occupation and education; maternal age and birth order. Residential location and socio-economic status were also analyzed for the Australian cases. Linear regression was used to determine relationships between these factors and age at diagnosis. A total of 909 cases were included. An older age of diagnosis was associated with later loss of hand function and speech, later onset of hand stereotypies and the presence of the p.R133C or p.R294X MECP2 mutation. Socio-economic factors did not predict age of diagnosis for Australian families. For families participating in the InterRett database, a younger age of diagnosis was associated with higher levels of parental education or occupation. A clinical picture consistent with the classic presentation of Rett syndrome is associated with an earlier diagnosis. Clinicians need to be alerted to the variable presentation of Rett syndrome including the milder phenotypes of cases with the p.R133C or p.R294X mutation. Educational resources to assist this understanding including guidance on when to request genetic testing could be useful to streamline the process of diagnosis in Rett syndrome.