Experiences of teachers in vocational programmes in special needs schools, City of Cape Town.

Background: Vocational programmes run by teachers in the special needs school context can play a significant role in the vocational development of learners with severe intellectual disability (SID). This study aimed to answer the question 'what are the challenges faced by teachers in the implementation of vocational programmes in selected public special needs schools for learners with SID in the Metropolitan (Metro) District within the City of Cape Town?' Objectives: The objectives were to describe the challenges as perceived by participants, to highlight common and contrasting challenges in the different schools and to share recommendations on support needed. Method: A qualitative descriptive study was conducted. A combination of purposive and snowball sampling strategies was used to select six teachers from six special needs schools. One-on-one semi-structured interviews with teachers were performed. An interview schedule was used as a tool and all interviews were transcribed and translated into English verbatim. Thematic analysis was applied. Results: The findings showed that teachers encounter inadequate resources, a lack of training, and poor support systems. This study highlights the issues of existing policy and the lack of a mandatory policy on vocational programmes in South Africa. Conclusion: The participants' experiences added to the existing literature by providing valuable insights into the obstacles teachers encounter in this relatively new curriculum. A multifaceted policy framework that is well funded and implemented is much needed to address the challenges identified. Contribution: The findings may contribute to the development and strengthening of policies on vocational programmes within the South African context.

Factors influencing communication partners of persons with severe/profound intellectual disability use of augmentative and alternative communication: an integrative review.

PURPOSE: To present a synthesis of evidence related to the factors influencing communication partners' use of augmentative and alternative communication with persons with severe/profound intellectual disability. MATERIALS AND METHODS: An integrative review guided by five steps; problem identification, literature search, data evaluation, data analysis and presentation was undertaken. In accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement, nine databases were searched, 1,342 studies were screened against the eligibility criteria, and 15 studies underwent thematic analysis. RESULTS: Two themes emerged; (1) Achieving Meaningful Communication and (2) Communication Partners' Preparedness to Use Augmentative and Alternative Communication. Achieving meaningful communication was central to communication partners' use of augmentative and alternative communication and was two-fold. It involved identifying the persons' communication methods and encouraging them to communicate. Communication partners' preparedness also influenced their use of augmentative and alternative communication. This preparedness was impacted by communication partners' preconceived thoughts about and knowledge of augmentative and alternative communication, nurturing their belief in augmentative and alternative communication, and the interpersonal dynamic between network members. CONCLUSION: Communication partners' use of augmentative and alternative communication is influenced by multiple and complex factors. The findings contribute to the knowledge of the potential factors to be considered to prepare communication partners to use augmentative and alternative communication.

Multiple, complex factors influence communication partners of persons with severe/profound intellectual disability use of augmentative and alternative communication (AAC), which include communication partners' beliefs, attitudes, expectations, knowledge and resources such as training, support and time.To offer individuals with severe/profound intellectual disability opportunities to communicate, communication partners need to recognise their attempts and thus, their ability. Continuously being sensitive to the individuals' communication methods, whilst being cognisant that these methods can change may enhance communication partners' awareness and understanding of the individuals' communication attempts.Communication partners' need to feel prepared to use AAC. To feel prepared, they need to be aware of the potential benefits that AAC can offer the interaction and the long-term outcomes, develop their knowledge, and be surrounded by a supportive team dynamic.

Sex-specific difference in phenotype of Kabuki syndrome type 2 patients: a matched case-control study.

BACKGROUND: Kabuki syndrome (KS) is a monogenic disorder leading to special facial features, mental retardation, and multiple system malformations. Lysine demethylase 6A, (KDM6A, MIM*300128) is the pathogenic gene of Kabuki syndrome type 2 (KS2, MIM#300867), which accounts for only 5%-8% of KS. Previous studies suggested that female patients with KS2 may have a milder phenotype. METHOD: We summarized the phenotype and genotype of KS2 patients who were diagnosed in Shanghai Children's Medical Center since July 2017 and conducted a 1:3 matched case-control study according to age and sex to investigate sex-specific differences between patients with and without KS2. RESULTS: There were 12 KS2 cases in this study, and 8 of them matched with 24 controls. The intelligence quotient (IQ) score of the case group was significantly lower than that of the control group (P < 0.001). In addition, both the incidence of intellectual disability (ID) (IQ < 70) and moderate-to-severe ID (IQ < 55) were significantly higher in the case group than those in the control group. No sex-specific difference was found in the incidence of ID or moderate-to-severe ID between the female cases and female controls, whereas there was a significant difference between male cases and male controls. Furthermore, the rate of moderate-to-severe ID and congenital heart disease (CHD) was significantly higher in the male group than that in the female group. CONCLUSIONS: Our results showed that a sex-specific difference was exhibited in the clinical phenotypes of KS2 patients. The incidence of CHD was higher in male patients, and mental retardation was significantly impaired. However, the female patients' phenotype was mild.

Behavioural activation for depressive symptoms in adults with severe to profound intellectual disabilities: Modelling and initial feasibility study.

BACKGROUND: Almost no research has been published reporting on evaluations of the effectiveness of psychological interventions for people with severe to profound intellectual disabilities and depression. This paper describes the development and initial feasibility testing of an adapted Behavioural Activation therapy (BeatIt2) for this population. METHOD: Phase 1 of the study examined participant recruitment and willingness to be randomised in the context of a planned Randomised Controlled Trial (RCT). Phase 2 examined the feasibility of delivering the intervention. RESULTS: Twenty adults with a severe or profound intellectual disability and clinically significant depression were recruited to Phase 1 of the study. In Phase 2, there was 100% participant retention for those recruited to the study at 6-month follow-up. The BeatIt2 therapy was reported to be acceptable for participants. CONCLUSION: COVID disruption meant that it was not possible to complete the planned feasibility RCT. The positive findings suggest that additional evaluation of BeatIt2 is warranted.

Adapting psychological interventions for people with severe and profound intellectual disabilities: A behavioural activation exemplar.

BACKGROUND: People with severe to profound intellectual disabilities experience similar or higher levels of depression than those with more mild intellectual disabilities. Yet, there is an absence of evidence about how to adapt existing psychological therapies for this population. METHOD: A behavioural activation intervention (BeatIt) for people with mild to moderate intellectual disabilities was adapted for people with severe to profound intellectual disabilities and depression. Key considerations include: (i) beginning with a more in-depth assessment process; (ii) including the person in session activities and developing a relationship with them; (iii) formulation and the use of film to document the link between activity and mood; and (iv) addressing barriers to change at an individual and inter-personal level and considering how the carer could support the person's engagement in activity. RESULTS: Successfully adapting BeatIt represents a first step towards gathering evidence about the effectiveness of behavioural activation for people with severe to profound intellectual disabilities.

A severe neurocognitive phenotype caused by biallelic CHD3 variants in two siblings.

CHD3 heterozygous variants are associated with Snijders Blok-Campeau syndrome (SBCS) which consists of intellectual disability (ID), macrocephaly, and dysmorphic facies. Most reported variants are missense or loss of function clustered within the ATPase/helicase domain of the protein. We report a severe neurocognitive phenotype caused by biallelic CHD3 variants in two siblings, each inherited from a mildly affected parent. Male and female siblings were referred to the Genetics Clinic due to severe ID and profound dysmorphism. The parents are first cousins of Iranian descent with borderline intellectual abilities. Exome sequencing was performed for the affected female and her parents. A single homozygous candidate variant in the CHD3 gene was detected in the proband: c.5384_5389dup. p.Arg1796_Phe1797insTrpArg, resulting in an in-frame insertion of 2 amino acids located outside the ATPase/helicase domain at the C-terminal region of CHD3-encoding residues. This variant is classified as likely pathogenic according to ACMG guidelines. The variant was detected in a heterozygous state in each parent. Both affected siblings were homozygous, while their unaffected brother did not carry the variant. Biallelic CHD3 variants cause a severe neurodevelopmental syndrome that is distinguishable from SBCS. We assume that the variant type (in-frame insertion) and location may enable CHD3 biallelic variants.

Mutación genética RAB11B: retraso psicomotor, braquicefalia, hipoplasia de cuerpo calloso. Primer caso descrito en España / Genetic mutation RAB11B: psychomotor retardation, brachycephaly, and corpus callosum hypoplasia. First case described in Spain

El complejo proteico RAB11B, miembro del complejo Rab GTPasa, codificado por el gen RAB11B, juega un papel importante en el desarrollo neuronal y en la formación de las funciones cognitivas. El gen RAB11B codifica un miembro de la subfamilia de las Rab11 GTPasas que se asocia con el reciclaje de las endosomas y participa en la regulación del tráfico de vesículas endoplásmicas. Se presenta el primer caso descrito en España de mutación en el gen RAB11B (mutación c.64G>A en heterocigosis), clínicamente caracterizado por retraso psicomotor, epilepsia, discapacidad intelectual, hipotonía, braquicefalia e hipoplasia del cuerpo calloso. Se realiza comparación del presente caso con otros cinco casos descritos a nivel mundial con la misma mutación, presentando las similitudes y rasgos distintivos(AU)

GTPase complex, encoded by the RAB11B gene, a member of the Rab protein complex which plays a significant role in neuronal development and the shaping of cognitive functions. The RAB11B gene encodes a member of the Rab11 GTPase subfamily that particularly associates with the recycling of endosomes and participates in the regulation of vesicular trafficking. We present the first case described in Spain of psychomotor retardation, intellectual disability due to a mutation in the RAB11B gene (c.64G>A mutation in heterozygosis), clinically characterized by psychomotor retardation, brachycephaly, corpus callosum hypoplasia, epilepsy and intellectual disability. The case is compared with other five cases described worldwide with the same mutation, presenting their similarities and distinctive features(AU)

Deep brain stimulation may be a viable option for resistant to treatment aggression in children with intellectual disability.

INTRODUCTION: Deep brain stimulation (DBS) is a surgical technique used to manage aggression in patients who do not improve despite the use of appropriate drug treatment. OBJECTIVE: The objective of this study is to assess the impact of DBS on aggressive behavior refractory to the pharmacological and behavioral treatment of patients with Intellectual Disabilities (ID). METHODS: A follow-up was conducted on a cohort of 12 patients with severe ID, undergoing DBS in posteromedial hypothalamic nuclei; evaluated with the Overt Aggression Scale (OAS), before the intervention, at 6, 12, and 18 months of medical follow-up. RESULTS: After the surgical procedure, there was a significant reduction in the aggressiveness of patients in the follow-up medical evaluation at 6 months (t = 10.14; p < 0.01), 12 months (t = 14.06; p < 0.01), and 18 months (t = 15.34; p < 0.01), respect to the initial measurement; with a very large effect size (6 months: d = 2.71; 12 months: d = 3.75; 18 months: d = 4.10). From 12 months onward, emotional control stabilized and is sustained at 18 months (t = 1.24; p > 0.05). CONCLUSION: DBS in posteromedial hypothalamic nuclei may be an effective treatment for the management of aggression in patients with ID refractory to pharmacological treatment.

Association of COVID-19-Related Restrictions With Changes in Functional Skills of Adults With Intellectual Disabilities in Day Programs of an Israeli Non-Profit Organization.

Intellectual disability (ID) is assumed to be a dynamic phenomenon influenced by personal and environmental factors. During the 18 months of the coronavirus disease (COVID-19) pandemic, most day centers remained open for adults with ID who lived with their families (most of them with severe/profound [S/P] ID) but were closed to those who lived in group homes (with moderate and mild ID). Owing to the fewer participants in day centers, adults with S/P ID received more hours of therapy than before the pandemic. Using a functional screening tool, functional and environmental changes were mapped and discussed in team meetings. As expected, the pandemic caused environmental and personnel changes that affected all groups. The moderate (n = 29) and mild (n = 31) groups deteriorated over the 18 months of the study, especially the senior ones. However, the functional state of the S/P group (n = 16) improved. These results support the understanding that ID is truly dynamic throughout the lifespan. Functional improvements for S/P ID can occur during adulthood with intense and individually adapted interventions.

Mutation in the STXBP1 Gene Associated with Early Onset West Syndrome: A Case Report and Literature Review.

Syntaxin-binding protein1 (STXBP1) is a member of the Sec1/Munc18-1 protein family, which comprises important regulators of the secretory and synaptic vesicle fusion machinery underlying hormonal and neuronal transmission, respectively. STXBP1 pathogenic variants are associated with multiple neurological disorders. Herein, we present the case of a Japanese girl with a mutation in the STXBP1 gene, who was born at 40 weeks without neonatal asphyxia. At 15 days old, she developed epilepsy and generalized seizures. Around 88 days old, she presented with a series of nodding spasms, with the seizure frequency gradually increasing. Interictal EEG indicated hypsarrhythmia and she presented with developmental regression. At 1.5 years old, genetic testing was performed and mutational analysis revealed an STXBP1 gene mutation (c.875G > A: p.Arg292His). Accordingly, she was diagnosed with developmental and epileptic encephalopathy, presenting West syndrome's clinical characteristics caused by the STXBP1 gene mutation. Although drug treatment has reduced the frequency of epileptic seizures, her development has remained regressive. The relationship between the location and type of genetic abnormality and the phenotype remains unclear. Future studies should investigate the genotype−phenotype correlation and the underlying pathophysiology to elucidate the causal relationships among the multiple phenotype-determining factors.

Recurrent pneumonia in three patients with MECP2 duplication syndrome with aspiration as the possible cause.

INTRODUCTION: Methyl-CpG binding protein 2 gene (MECP2) is located on the X chromosome (Xq28) and is important for nervous and immune system functioning. Patients with MECP2 duplication syndrome (MDS) have recurrent respiratory infections (RRIs). Although RRIs often occur with MDS because some patients with MDS also have hypoimmunoglobulinemia and duplication of the interleukin-1-receptor-associated kinase-1 gene (IRAK1), which is also located on Xq28, the phenotype of IRAK1 duplication in patients with MDS remains unclear. METHODS: The clinical course of three patients with MDS who underwent laryngotracheal separation (LTS) at two institutions was summarized. RESULTS: Three patients with MDS were identified to have recurrent pneumonia characteristic of aspiration pneumonia, sometimes requiring artificial ventilation therapy; they had no other bacterial infections. After LTS, they rarely had pneumonia. In MDS, MECP2 expression increased two-fold naturally, while IRAK-1 expression showed no difference compared with a healthy subject. CONCLUSIONS: Since RRIs in MDS are thought to be caused by aspiration and not susceptibility to infection previously estimated to be major complication, the evaluation of aspiration is recommended for RRIs for better management of MDS.

Postoperative dysphagia caused by a delay in mandibular fracture treatment in a patient with severe intellectual disability: a case report.

BACKGROUND: The postoperative complications of mandibular fracture include malocclusion, infection, nonunion, osteomyelitis, and sensorial mental nerve dysfunction. However, there are no reports regarding postoperative dysphagia as a complication of mandibular fracture. Herein, we report a rare case of postoperative dysphagia caused by delayed mandibular fracture treatment in a patient with severe intellectual disability. CASE PRESENTATION: A 46-year-old Japanese male patient with severe intellectual disability fell down and struck his chin. The patient was referred to our department 10 days after the accident. Upon examination, he could not close his mouth because of severe left mandibular body fracture. Open reduction and internal fixation was performed under general anesthesia 16 days after sustaining the injury, and normal occlusion was eventually achieved. However, the patient could not swallow well a day after surgery. He was then diagnosed with postoperative dysphagia caused by disuse atrophy of muscles for swallowing based on videoendoscopic examination findings. Adequate dysphagia rehabilitation could not be facilitated because of the patient's mental status. Postoperative dysphagia did not improve 21 days after surgery. Therefore, percutaneous endoscopic gastrostomy was required. CONCLUSIONS: The treatment course of the patient had two important implications. First, postoperative dysphagia caused by disuse atrophy may occur if treatment is delayed in severe mandibular body fracture. Second, in particular, if a patient with severe intellectual disability develops postoperative dysphagia caused by disuse atrophy, adequate dysphagia rehabilitation cannot be facilitated, and percutaneous endoscopic gastrostomy may be required. Therefore, early open reduction and internal fixation is required for mandibular fracture in a patient with severe intellectual disability.

Exploring co-occurrence of sensory, motor and neurodevelopmental problems and epilepsy in children with severe-profound intellectual disability.

BACKGROUND: Severe to profound intellectual disability (SPID) is associated with multiple neurodevelopmental disorders and problems. In the most severe cases, the term profound intellectual and multiple disabilities (PIMD) is used. This study aimed to explore the co-occurring disorders and neurodevelopmental problems in a sample of twins where the proband had SPID. METHOD: Within a population-based sample of (30 312) twins, 20 individuals with a national patient register SPID diagnosis were identified. Parent telephone interview data (screening of neurodevelopmental disorders) and register data (APGAR, birth weight, intellectual disabilities, epilepsy, motor and sensory disorders) were gathered for probands and co-twins. RESULTS: The 20 individuals with SPID all had between one and five additional disorders or problems, with autistic traits, motor problems and epilepsy being the most common. Clear discordance was found for ID and all additional disorders and problems between probands with SPID and their non-SPID co-twins. CONCLUSION: Children with SPID almost never present without neurodevelopmental and/or sensory and/or motor comorbidities. This heterogeneity should be reflected in clinical routine and in research targeting individuals with SPID. The results support a previously suggested conceptualization of a S/PIMD "spectrum". Autism may be considered for inclusion in future elaborations of such a S/PIMD spectrum.

Case study: identification of anxiety and subsequent intervention in an adolescent male with autism, severe intellectual disability and self-injurious behaviour.

Introduction: Anxiety disorders are highly prevalent in individuals with autism spectrum disorder (ASD), but knowledge is limited regarding identification and treatment of these disorders in individuals with ASD and more severe levels of intellectual disability (ID). The current case study aims to explore and describe the inpatient, psychiatric assessment in an adolescent male with ASD, severe ID and self-injurious behaviour (SIB) who was diagnosed with a co-occurring anxiety disorder. The study further aims to explore the implications of this diagnosis for subsequent intervention and care, including management of SIB. Materials and methods: Case study including multimodal, psychiatric assessment and subsequent intervention. Results: Following changes in care strategies attempting to incorporate the understanding of anxiety/trauma as contributing to SIB, a reduction of SIB was observed, and this reduced frequency was maintained when the patient was discharged from the inpatient setting. Conclusions: Though no causal inferences are possible, these experiences indicate that further research is needed regarding possible associations between SIB and anxiety in individuals with ASD, including implications for treatment. Experiences from the current case further indicate that it is possible to recognize and diagnose anxiety disorder in complex cases involving ASD, severe ID, limited verbal language skills, and severe SIB.

Exploring quality of life in individuals with a severe developmental and epileptic encephalopathy, CDKL5 Deficiency Disorder.

BACKGROUND: CDKL5 Deficiency Disorder (CDD) is a rare genetic disorder caused by a mutation in the cyclin-dependent kinase-like 5 (CDKL5) gene. It is now considered to be a developmental and epileptic encephalopathy because of the early onset of seizures in association with severe global delay. Other features include cortical visual impairment, sleep and gastro-intestinal problems. Progress in clinical understanding, especially regarding the spectrum of functional ability, seizure patterns, and other comorbidities was initially slow but accelerated in 2012 with the establishment of the International CDKL5 Database (ICDD). Our aim was to use this data source to investigate quality of life (QOL) and associated factors in this disorder. METHOD: A follow-up questionnaire was administered in 2018 to parents of children registered with the ICDD who had a pathogenic CDKL5 variant. QOL was assessed using QI Disability, an instrument, specifically developed to measure total and specific domains of QOL (physical health, positive emotions, negative emotions, social interaction, leisure and the outdoors (leisure) and independence) in children with intellectual disability. Associations with functional abilities, physical health, mental health and family factors were investigated, initially using univariate analyses followed by multivariate analyses for each of these groups with a final composite model which included the important variables identified from previous models. RESULTS: Questionnaires were returned by 129/160 families with a child aged >3 years. Functional impairment, including lack of ability to sit, use hands and communicate had the greatest adverse impact on QOL. There were also some relationships with major genotype groupings. Individuals using three or more anti-epileptic medications had poorer QOL than those on one or no medication, particularly in the physical health domain. There was also variation by geographical region with those living in North America typically having the best QOL and those living in middle or lower income countries poorer QOL. CONCLUSION: Although lower functional abilities were associated with poorer quality of life further research is needed to understand how environmental supports might mitigate this deficit. Comprehensive care and support for both the child and family have important roles to play in helping families to thrive despite the severity of CDD.

Assessment and Classification of Severe Intellectual Disability for Children Aged 6-18 / 中国康复理论与实践

Objective To explore the assessment and classification for children aged 6-18 with severe intellectual disability.Methods A total of 36 children with severe intellectual disability were assessed with Wechsler Preschool and Primacy Scale of Intelligence (WPPSI-Ⅳ) (CN) and Adaptive Behavior Assessment System (ABAS-Ⅱ) (CNC).Results The ratio intelligence quotient of WPPSI-Ⅳ was (32.4±4.91), consistent with the results from ABAS-Ⅱ.Conclusion WPPSI-Ⅳ and ABAS-Ⅱ can be used for assessment and classification of severity of intellectual disability for children aged 6-18 and intelligence quotient less than 45.

Whole genome sequencing identifies a de novo 2.1 Mb balanced paracentric inversion disrupting FOXP1 and leading to severe intellectual disability.

The FOXP1 gene, located on chromosome 3p13, encodes the Forkhead-box protein P1, one of the four forkhead transcription factors which repress transcription by forming active homo- and heterodimers and regulate distinct patterns of gene expression crucial for embryogenesis and normal development. FOXP1 mutations, mostly truncating, have been described in patients with mild to moderate intellectual disability (ID), autism spectrum disorder (ASD), and speech and language impairment (MIM #613670). Here, we report a small de novo heterozygous balanced inversion of 2.1 Mb located at 3p14.1p13 identified by Whole Genomic Sequencing (WGS) and disrupting the genes FAM19A4 and FOXP1. This inversion was found in a patient with severe ID, ASD, seizures and very unusual vascular anomalies which were never described in the clinical spectrum of FOXP1 mutations. We show that the neurodevelopmental phenotype observed in the patient most likely results from FOXP1 haploinsufficiency as this heterozygous inversion leads to a 60 to 85% decrease of FOXP1 mRNA levels and to the complete absence of FOXP1 full-length protein. These findings, in addition to expanding the molecular spectrum of FOXP1 mutations, emphasize the emerging role of WGS in identifying small balanced chromosomal rearrangements responsible for neurodevelopmental disorders and not detected by conventional cytogenetics.

Transition from school to adult services for young people with severe or profound intellectual disability: A systematic review utilizing framework synthesis.

BACKGROUND: The transition to adulthood has been described as a difficult time in the lives of young people with intellectual disability. There has been little emphasis on young people with severe or profound intellectual disability specifically, even though their pathways may differ, due to greater support needs across the life course. METHODS: A systematic review was conducted utilising Bronfenbrenner's ecological model to inform framework analysis to synthesise qualitative findings. RESULTS: Taking an ecological perspective proved valuable. The transition process was described as stressful and barriers were identified across the ecological levels. Parents accounted for the majority of participants in studies, and the needs of young people and their parents emerged as highly interdependent. CONCLUSION: Themes reflect the complex nature of the question what adulthood should look like for individuals with severe or profound intellectual disability. There is a lack of involvement of multiple stakeholders and young people themselves within studies.

Further evidence for GRIN2B mutation as the cause of severe epileptic encephalopathy.

Epileptic encephalopathies (EE) include a range of severe epilepsies in which intractable seizures or severe sub-clinical epileptiform activity are accompanied by impairment of motor and cognitive functions. Mutations in several genes including ion channels and other genes whose function is not completely understood have been associated to some EE. In this report, we provide a detailed clinical description of a sporadic male patient with early-onset epilepsy and epileptic encephalopathy in whom we performed complete exome sequencing (WES) and identified a GRIN2B mutation. The GRIN2B splicing mutation in intron 10 (c.2011-1G>A) was revealed in a WES study. The result was confirmed by Sanger sequencing. No mutation was found in both parents. Our finding confirms that early-onset EE may be caused not only by gain-of-function variants but also by splice site mutations-in particular those affecting the splice acceptor site of the 10th intron of the GRIN2B gene. © 2016 Wiley Periodicals, Inc.

A novel MED12 mutation: Evidence for a fourth phenotype.

Mutations of the MED12 gene have been reported mainly in males with FG (Opitz-Kaveggia), Lujan-Fryns, or X-linked Ohdo syndromes. Recently, a different phenotype characterized by minor anomalies, severe intellectual disability (ID), and absent language was reported in female and male patients belonging to the same family and carrying a frameshift MED12 mutation (c.5898dupC). Here, we report on two brothers and their niece affected by severe and mild ID, respectively, where whole exome sequencing combined with variant analysis within a panel of ID-related genes, disclosed a novel c.2312T>C (p.Ile771Thr) MED12 mutation. This variant, which has not been reported as a polymorphism, was not present in a third unaffected brother, and was predicted to be deleterious by five bioinformatic databases. This finding together with the phenotypic analogies shared with the carriers of c.5898dupC mutation suggests the existence of a fourth MED12-related disorder, characterized by severe ID, absent or deficient language and, milder, clinical manifestation in heterozygotes. We have reviewed the literature on MED12 heterozygotes, their clinical manifestations, and discuss the possible biological causes of this condition. © 2016 Wiley Periodicals, Inc.