Rett syndrome (RTT; OMIM#312750) is a severe neurodevelopmental disorder that affects mainly girls. It has an estimated incidence of 1:10 000 -15 000 females. Mutations in the X-linked gene methyl CpGbinding protein 2 (MECP2) have been found in most patients. The most accepted explanation for the sex bias is that the Rett mutation in sporadic cases has its origin in the paternal germline X chromosome and can thus only be transmitted to females. The majority of cases are sporadic (99.5%) but some familial cases have been described. These cases can either be explained by germline mosaicism or by asymptomatic carrier mothers with skewing of X-inactivation towards the wild-type MECP2 allele. We describe one of the few familial cases of RTT in which a maternal germline mosaicism is the most likely explanation. The mutation p.Arg270fs (c.808delC) was identified in both a girl with classical RTT and her brother who had the severe neurological phenotype usually described in males. The mutation was absent in DNA extracted from blood of both parents. These type of events must be taken into consideration in the genetic counselling of families after the diagnosis of a first case of RTT in a female or a MECP2 mutation in a male.

Background: The diagnosis of Rett syndrome (RTT) is based on a set of clinical criteria, irrespective of mutation status. The aims of this study were (1) to define the clinical differences existing between patients with Rett syndrome with (Group I) and without a MECP2 mutation (Group II), and (2) to characterize the phenotypes associated with the more common MECP2 mutations. Patients and methods: We analyzed 87 patients fulfilling the clinical criteria for RTT. All were observed and videotaped by the same paediatric neurologist. Seven common mutations were considered separately, and associated clinical features analysed. Results: Comparing Group I and II, we found differences concerning psychomotor development prior to onset, acquisition of propositive manipulation and language, and evolving autistic traits. Based on age at observation, we found differences in eye pointing, microcephaly, growth, number of stereotypies, rigidity, ataxia and ataxic-rigid gait, and severity score. Patients with truncating differed from those with missense mutations regarding acquisition of propositive words and independent gait, before the beginning of the disease, and microcephaly, growth, foot length, dystonia, rigidity and severity score, at the time of observation. Patients with the R168X mutation had a more severe phenotype, whereas those with R133C showed a less severe one. Patients with R294X had a hyperactive behaviour, and those with T158M seemed to be particularly ataxic and rigid. Conclusion: A clear regressive period (with loss of prehension and language, deceleration of growth) and the presence of more than three different stereotypies, rigidity and ataxic-rigid gait seemed to be very helpful in differentiating Group I from Group II.

Introduction: The Centro de Estudos do Bebé e da Criança in Hospital Dona Estefânia has organized a multidisciplinary model for children under three with suspected autism spectrum disorder, thus implementing the recent guidelines established by the Directorate General for Health. The aim of this study is to describe this model and case series.Material and Methods: A retrospective descriptive study of observed children with suspected ASD. They were observed according to the model of the Centro de Estudos do Bebé e da Criança and DC:0-5TM classification, between January 2018 and September 2019.Results: The study included 178 children. The average age at the initial assessment was 27 months. From the total sample, 116 children concluded the diagnostic sessions (axis I): Autism Spectrum Disorder/Early Atypical (36%), Developmental Language Disorder (18%), Other (19%). Factors of axes II, III, IV and V of DC:0-5TM were determinant for clinical diagnosis in 26%.Discussion: Of 116 children, 36% were diagnosed with Autism Spectrum Disorder. This highlights the diagnostic challenge posed by neurodevelopmental disorders in early infancy. The sample shows that the characteristics of the relationship with the caregiver (axis II), presence of physical conditions (axis III), psycho-social stressors (axis IV) and developmental trajectory (axis V) have a significant clinical impact. In the future, the initial assessment should take place well before the age of 27 months because of the impact on prognosis.Conclusion: This model is a pioneering approach in Portugal. It promotes a common approach of Child and Adolescent Psychiatry and Neuropediatrics/Developmental Pediatrics in early infancy. Moreover, it increases the diagnostic acuity of Autism Spectrum Disorders and early therapeutic intervention.

Head injury is a leading cause of mortality and acquired neurological impairment in children. Head-injured children may have neurobehavioural deficits that persist for years following injury. Head injury can result in significant and persistent caregiver burden, including mental health issues, family stress and disorganisation, and unmet social and healthcare service needs. Few studies have examined the healthcare and social service needs of children and their families following head injury sustained at an early age. This qualitative study aims to describe the experiences of caregivers of children who sustained a serious head injury (particularly non-accidental head injury) before the age of 2 years. Caregivers were interviewed up to 15 years following the initial injury. Semi-structured interviews with 21 caregivers of 15 children (aged 3-15 years at the time of interview) were completed. Thematic analysis of interview data generated three key themes: impact, support and information. The study's findings reveal the broad impact of serious childhood head injury on caregivers, specifically the significant distress and burden brought about through lack of information, challenges in accessing support and inconsistent care. Recommendations for developing a quality 'model of care' and improving ease of access to supports for caregivers are provided.

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is a common X-linked enzyme abnormality. The clinical phenotype is variable but often predictable from the molecular lesion. Class I variants (the most severe forms of the disease) cluster within exon 10, in a region that, at the protein level, is believed to be involved in dimerization. Here we describe a de novo mutation (C269Y) of a new class I variant (G6PD Aveiro) that maps to exon 8. Mutant and normal alleles were found in both hematopoietic and buccal cells, indicating the presence of mosaicism. The available model of the protein predicts that this lesion lies in proximity to the dimer interface of the molecule. A possible mechanism to explain the severity of the defect is proposed.