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Background: Biallelic SUFU variants have originally been linked to Joubert syndrome, comprising cerebellar abnormalities, dysmorphism, and polydactyly. In contrast, heterozygous truncating variants have recently been associated with developmental delay and ocular motor apraxia, but only a limited number of patients have been reported. Here, we aim to delineate further the mild end of the phenotypic spectrum related to SUFU haploinsufficiency., Methods: Nine individuals (from three unrelated families) harboring truncating SUFU variants were investigated, including two previously reported individuals (from one family). We provide results from a comprehensive assessment comprising neuroimaging, neuropsychology, video-oculography, and genetic testing., Results: We identified three inherited or de novo truncating variants in SUFU (NM_016169.4): c.895C>T p.(Arg299∗), c.71dup p.(Ala25Glyfs∗23), and c.71del p.(Pro24Argfs∗72). The phenotypic expression showed high variability both between and within families. Clinical features include motor developmental delay (seven of nine), axial hypotonia (five of nine), ocular motor apraxia (three of nine), and cerebellar signs (three of nine). Four of the six reported children had macrocephaly. Neuropsychological and developmental assessments revealed mildly delayed language development in the youngest children, whereas general cognition was normal in all variant carriers. Subtle but characteristic SUFU-related neuroimaging abnormalities (including superior cerebellar dysplasia, abnormalities of the superior cerebellar peduncles, rostrally displaced fastigium, and vermis hypoplasia) were observed in seven of nine individuals., Conclusions: Our data shed further light on the mild but recognizable features of SUFU haploinsufficiency and underline its marked phenotypic variability, even within families. Notably, neurodevelopmental and behavioral abnormalities are mild compared with Joubert syndrome and seem to be well compensated over time., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

Childhood apraxia of speech (CAS) is a severe and rare form of speech sound disorder (SSD). CAS is typically sporadic, but may segregate in families with broader speech and language deficits. We hypothesize that genetic changes may be involved in the etiology of CAS. We conduct whole-genome sequencing in 27 families with CAS, 101 individuals in all. We identify 17 genomic regions including 19 unique copy number variants (CNVs). Three variants are shared across families, but the rest are unique; three events are de novo. In four families, siblings with milder phenotypes co-inherited the same CNVs, demonstrating variable expressivity. We independently validate eight CNVs using microarray technology and find many of these CNVs are present in children with milder forms of SSD. Bioinformatic investigation reveal four CNVs with substantial functional consequences (cytobands 2q24.3, 6p12.3-6p12.2, 11q23.2-11q23.3, and 16p11.2). These discoveries show that CNVs are a heterogeneous, but prevalent, cause of CAS., (© 2024. The Author(s).)

Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Purpose: Advancements in genetic testing and analysis have allowed improved identification of the genetic basis of childhood apraxia of speech, a rare speech presentation. This study aimed to understand speech-language pathologists' (SLPs') consideration of incorporation of genetics in clinical practice using a theory-informed qualitative approach., Method: Semistructured interviews were conducted with 12 pediatric SLPs using a behavior change theory (Theoretical Domains Framework [TDF]) within a case study describing a child with complex co-occurring features, including childhood apraxia of speech. Interviews focused on three stages of the patient journey (prereferral, referral, and postreferral). Interviews were analyzed to identify barriers and enablers to considering incorporation of genetics in current clinical practice. Barriers and enablers were grouped and mapped onto a contextually relevant TDF-coded analysis framework., Results: Barriers were identified across several TDF domains, through all stages of the patient journey. Lack of confidence, relevance, and level of experience were most common prereferral, and connection to and awareness of genetics services and contextual factors were barriers in the referral stage. Perception of professional role, knowledge, and beliefs about effects on families were barriers postreferral. Associated enablers were also identified, including seeing value in genetic diagnosis, support from other health care professionals, supervision, and relationships with genetics services., Conclusions: Results of this qualitative study highlight barriers and enablers to incorporating genetics into speech-language pathology clinical practice. These findings will assist in the development of theory-informed implementation strategies to support SLPs into the future., Supplemental Material: https://doi.org/10.23641/asha.24112800.

Severe speech disorders lead to poor literacy, reduced academic attainment and negative psychosocial outcomes. As early as the 1950s, the familial nature of speech disorders was recognized, implying a genetic basis; but the molecular genetic basis remained unknown. In 2001, investigation of a large three generational family with severe speech disorder, known as childhood apraxia of speech (CAS), revealed the first causative gene; FOXP2. A long hiatus then followed for CAS candidate genes, but in the past three years, genetic analysis of cohorts ascertained for CAS have revealed over 30 causative genes. A total of 36 pathogenic variants have been identified from 122 cases across 3 cohorts in this nascent field. All genes identified have been in coding regions to date, with no apparent benefit at this stage for WGS over WES in identifying monogenic conditions associated with CAS. Hence current findings suggest a remarkable one in three children have a genetic variant that explains their CAS, with significant genetic heterogeneity emerging. Around half of the candidate genes identified are currently supported by medium (6 genes) to strong (9 genes) evidence supporting the association between the gene and CAS. Despite genetic heterogeneity; many implicated proteins functionally converge on pathways involved in chromatin modification or transcriptional regulation, opening the door to precision diagnosis and therapies. Most of the new candidate genes for CAS are associated with previously described neurodevelopmental conditions that include intellectual disability, autism and epilepsy; broadening the phenotypic spectrum to a distinctly milder presentation defined by primary speech disorder in the setting of normal intellect. Insights into the genetic bases of CAS, a severe, rare speech disorder, are yet to translate to understanding the heritability of more common, typically milder forms of speech or language impairment such as stuttering or phonological disorder. These disorders likely follow complex inheritance with polygenic contributions in many cases, rather than the monogenic patterns that underly one-third of patients with CAS. Clinical genetic testing for should now be implemented for individuals with CAS, given its high diagnostic rate, which parallels many other neurodevelopmental disorders where this testing is already standard of care. The shared mechanisms implicated by gene discovery for CAS highlight potential new targets for future precision therapies., (© 2024. The Author(s).)

Pathogenic variants in BRPF1 cause intellectual disability, ptosis and facial dysmorphism. Speech and language deficits have been identified as a manifestation of BRPF1-related disorder but have not been systematically characterized. We provide a comprehensive delineation of speech and language abilities in BRPF1-related disorder and expand the phenotype. Speech and language, and health and medical history were assessed in 15 participants (male = 10, median age = 7 years 4 months) with 14 BRPF1 variants. Language disorders were common (11/12), and most had mild to moderate deficits across receptive, expressive, written, and social-pragmatic domains. Speech disorders were frequent (7/9), including phonological delay (6/9) and disorder (3/9), and childhood apraxia of speech (3/9). All those tested for cognitive abilities had a FSIQ ≥70 (4/4). Participants had vision impairment (13/15), fine (8/15) and gross motor delay (10/15) which often resolved in later childhood, infant feeding impairment (8/15), and infant hypotonia (9/15). We have implicated BRPF1-related disorder as causative for speech and language disorder, including childhood apraxia of speech. Adaptive behavior and cognition were strengths when compared to other monogenic neurodevelopmental chromatin-related disorders. The universal involvement of speech and language impairment is noteable, relative to the high degree of phenotypic variability in BRPF1-related disorder., (Copyright © 2024. Published by Elsevier Masson SAS.)

Childhood apraxia of speech (CAS) is a pediatric motor speech disorder. The genetic etiology of this complex neurological condition is not yet well understood, although some genes have been linked to it. We describe the case of a boy with a severe and persistent motor speech disorder, consistent with CAS, and a coexisting language impairment.Whole exome sequencing in our case revealed a de novo and splicing mutation in the CSMD1 gene., Competing Interests: None declared., (Thieme. All rights reserved.)

CTNNB1 syndrome is an autosomal-dominant neurodevelopmental disorder featuring developmental delay; intellectual disability; behavioral disturbances; movement disorders; visual defects; and subtle facial features caused by de novo loss-of-function variants in the CTNNB1 gene. Due to paucity of data, this study intends to describe feeding issues and oral-motor dyspraxia in an unselected cohort of 10 patients with a confirmed molecular diagnosis. Pathogenic variants along with key information regarding oral-motor features were collected. Sialorrhea was quantified using the Drooling Quotient 5. Feeding abilities were screened using the Italian version of the Montreal Children's Hospital Feeding Scale (I-MCH-FS). Mild-to-severe coordination difficulties in single or in a sequence of movements involving the endo-oral and peri-oral muscles were noticed across the entire cohort. Mild-to-profuse drooling was a commonly complained-about issue by 30% of parents. The mean total I-MCH-FS t-score equivalent was 43.1 ± 7.5. These findings contribute to the understanding of the CTNNB1 syndrome highlighting the oral motor phenotype, and correlating specific gene variants with clinical characteristics.

Purpose: LAMA 1 gene as a pathologic variant leading to cerebellar dysplasia and cysts, nonprogressive ataxia, language, and motor developmental delay without any muscular involvement was recently described as Poretti-Boltshauser syndrome (PBS). Ocular involvement is a common associated feature in this neurodegenerative disorder. In this case report, we describe the retinal changes associated with Poretti-Boltshauser syndrome., Methods, Patient, and Results: A 4-year-old female child presented with the progressive decreased vision for the past 6 to 8 months. Ophthalmic examination revealed mild myopia and ocular motor apraxia with retinal disruptions appearing as holes that were confined only to inner retinal layers. The child also had motor and speech developmental delays. Magnetic resonance imaging of the brain showed vermis hypoplasia with cerebellar dysgenesis and multiple cystic spaces in both cerebellar hemispheres. Whole exome sequencing revealed a homozygous pathogenic variant of exon 2-63 deletion in the LAMA 1 gene, which was confirmatory for Poretti-Boltshauser syndrome., Conclusion: Oculomotor apraxia and retinal changes can lead to visual disturbances in Poretti-Boltshauser syndrome. Identification of these features and prompt rehabilitative measures can improve the quality of life of these children.

Speech and language impairments are central features of CDK13-related disorder. While pathogenic CDK13 variants have been associated with childhood apraxia of speech (CAS), a systematic characterisation of communication has not been conducted. Here we examined speech, language, non-verbal communication skills, social behaviour and health and development in 41 individuals with CDK13-related disorder from 10 countries (male = 22, median-age 7 years 1 month, range 1-25 years; 33 novel). Most participants used augmentative and alternative communication (AAC) in early childhood (24/41). CAS was common (14/22). Performance varied widely across intellectual ability, social behaviour and expressive language skills, with participants ranging from within average through to the severely impaired range. Receptive language was significantly stronger than expressive language ability. Social motivation was a relative strength. In terms of a broader health phenotype, a quarter had one or more of: renal, urogenital, musculoskeletal, and cardiac malformations, vision impairment, ear infections and/or sleep disturbance. All had gross and fine motor impairments (41/41). Other conditions included mild-moderate intellectual disability (16/22) and autism (7/41). No genotype-phenotype correlations were found. Recognition of CAS, a rare speech disorder, is required to ensure appropriately targeted therapy. The high prevalence of speech and language impairment underscores the importance of tailored speech therapy, particularly early access to AAC supports., (© 2022. The Author(s), under exclusive licence to European Society of Human Genetics.)

Limited evidence for early indicators of childhood apraxia of speech (CAS) precludes reliable diagnosis before 36 months, although a few prior studies have identified several potential early indicators. We examined these possible early indicators in 10 toddlers aged 14-24 months at risk for CAS due to a genetic condition: 7q11.23 duplication syndrome (Dup7). Phon Vocalisation analyses were conducted on phonetic transcriptions of each child's vocalisations during an audio-video recorded 30-minute play session with a caregiver and/or a trained research assistant. The resulting data were compared to data previously collected by Overby from similar-aged toddlers developing typically (TD), later diagnosed with CAS (LCAS), or later diagnosed with another speech sound disorder (LSSD). The Dup7 group did not differ significantly from the LCAS group on any measure. In contrast, the Dup7 group evidenced significant delays relative to the LSSD group on canonical babble frequency, volubility, consonant place diversity, and consonant manner diversity and relative to the TD group not only on these measures but also on canonical babble ratio, consonant diversity, and vocalisation structure diversity. Toddlers with Dup7 also demonstrated expressive vocabulary delay as measured by both number of word types orally produced during the play sessions and primary caregivers' responses on a standardised parent-report measure of early expressive vocabulary. Examining babble, phonetic, and phonotactic characteristics from the productions of young children may allow for earlier identification of CAS and a better understanding of the nature of CAS.

Background: Heterozygous disruptions of FOXP2 were the first identified molecular cause for severe speech disorder: childhood apraxia of speech (CAS), and yet few cases have been reported, limiting knowledge of the condition., Methods: Here we phenotyped 28 individuals from 17 families with pathogenic FOXP2 -only variants (12 loss-of-function, five missense variants; 14 males; aged 2 to 62 years). Health and development (cognitive, motor, social domains) were examined, including speech and language outcomes with the first cross-linguistic analysis of English and German., Results: Speech disorders were prevalent (23/25, 92%) and CAS was most common (22/25, 88%), with similar speech presentations across English and German. Speech was still impaired in adulthood, and some speech sounds (eg, 'th', 'r', 'ch', 'j') were never acquired. Language impairments (21/25, 84%) ranged from mild to severe. Comorbidities included feeding difficulties in infancy (10/26, 38%), fine (13/26, 50%) and gross (13/26, 50%) motor impairment, anxiety (5/27, 19%), depression (6/27, 22%) and sleep disturbance (10/24, 42%). Physical features were common (22/27, 81%) but with no consistent pattern. Cognition ranged from average to mildly impaired and was incongruent with language ability; for example, seven participants with severe language disorder had average non-verbal cognition., Conclusions: Although we identify an increased prevalence of conditions like anxiety, depression and sleep disturbance, we confirm that the consequences of FOXP2 dysfunction remain relatively specific to speech disorder, as compared with other recently identified monogenic conditions associated with CAS. Thus, our findings reinforce that FOXP2 provides a valuable entry point for examining the neurobiological bases of speech disorder., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2023. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Childhood apraxia of speech (CAS), the prototypic severe childhood speech disorder, is characterized by motor programming and planning deficits. Genetic factors make substantive contributions to CAS aetiology, with a monogenic pathogenic variant identified in a third of cases, implicating around 20 single genes to date. Here we aimed to identify molecular causation in 70 unrelated probands ascertained with CAS. We performed trio genome sequencing. Our bioinformatic analysis examined single nucleotide, indel, copy number, structural and short tandem repeat variants. We prioritised appropriate variants arising de novo or inherited that were expected to be damaging based on in silico predictions. We identified high confidence variants in 18/70 (26%) probands, almost doubling the current number of candidate genes for CAS. Three of the 18 variants affected SETBP1, SETD1A and DDX3X, thus confirming their roles in CAS, while the remaining 15 occurred in genes not previously associated with this disorder. Fifteen variants arose de novo and three were inherited. We provide further novel insights into the biology of child speech disorder, highlighting the roles of chromatin organization and gene regulation in CAS, and confirm that genes involved in CAS are co-expressed during brain development. Our findings confirm a diagnostic yield comparable to, or even higher, than other neurodevelopmental disorders with substantial de novo variant burden. Data also support the increasingly recognised overlaps between genes conferring risk for a range of neurodevelopmental disorders. Understanding the aetiological basis of CAS is critical to end the diagnostic odyssey and ensure affected individuals are poised for precision medicine trials., (© 2022. The Author(s).)

Poretti-Boltshauser syndrome (PTBHS) is an autosomal recessive disorder characterized by cerebellar dysplasia with cysts and an abnormal shape of the fourth ventricle on neuroimaging, due to pathogenic variants in the LAMA1 gene. The clinical spectrum mainly consists of neurological and ophthalmological manifestations, including non-progressive cerebellar ataxia, oculomotor apraxia, language impairment, intellectual disability, high myopia, abnormal eye movements and retinal dystrophy. We report a patient presenting with ventriculomegaly on antenatal neuroimaging and a neonatal diagnosis of Type III esophageal atresia. She subsequently developed severe myopia and strabismus with retinal dystrophy, mild developmental delay, and cerebellar dysplasia. Genetic investigations confirmed PTBHS. This report confirms previous reports of antenatal ventriculomegaly in PTBHS patients and documents a so far unreported occurrence of esophageal atresia in PTBHS. We additionally gathered phenotype and genotype descriptions of published cases in an effort to better define the spectrum of PTBHS., (Copyright © 2023 Elsevier Masson SAS. All rights reserved.)

Pathogenic KAT6A variants cause syndromic neurodevelopmental disability. "Speech delay" is reported, yet none have examined specific speech and language features of KAT6A syndrome. Here we phenotype the communication profile of individuals with pathogenic KAT6A variants. Medical and communication data were acquired via standardized surveys and telehealth-assessment. Forty-nine individuals (25 females; aged 1;5-31;10) were recruited, most with truncating variants (44/49). Intellectual disability/developmental delay (42/45) was common, mostly moderate/severe, alongside concerns about vision (37/48), gastrointestinal function (33/48), and sleep (31/48). One-third (10/31) had a diagnosis of autism. Seventy-three percent (36/49) were minimally-verbal, relying on nonverbal behaviors to communicate. Verbal participants (13/49) displayed complex and co-occurring speech diagnoses regarding the perception/production of speech sounds, including phonological impairment (i.e., linguistic deficits) and speech apraxia (i.e., motor planning/programming deficits), which significantly impacted intelligibility. Receptive/expressive language and adaptive functioning were also severely impaired. Truncating variants in the last two exons of KAT6A were associated with poorer communication, daily-living skills, and socialization outcomes. In conclusion, severe communication difficulties are present in KAT6A syndrome, typically on a background of significant intellectual disability, vision, feeding and motor deficits, and autism in some. Most are minimally-verbal, with apparent contributions from underlying motor deficits and cognitive-linguistic impairment. Alternative/augmentative communication (AAC) approaches are required for many into adult life. Tailored AAC options should be fostered early, to accommodate the best communication outcomes., (© 2022 Wiley Periodicals LLC.)

BCL11A is implicated in BCL11A-Related Intellectual Development Disorder (BCL11A-IDD). Previously reported cases had various types of BCL11A variants (copy-number variations [CNVs], singlenucleotide variants [SNVs]). Phenotypes included global, cognitive, and motor delays, autism spectrum disorder (ASD), craniofacial dysmorphology, and speech and language delays described generally, with only two reports specifying childhood apraxia of speech (CAS). Here, we present three additional children with CAS and de novo BCL11A variants, a p.Ala182Thr nonconservative missense and a p.GLu611.Ter nonsense variant, both in exon 4, and a 106 kb deletion harboring exons 1 and 2. All three children have fine and gross motor discoordination, feeding difficulties, and visual motor disorders. Intellectual and learning disabilities and disordered language skills were seen only in the child with the missense variant and the child with the deletion. These findings align with, and expand, previous findings in that BCL11A variants have significant and highly penetrant apraxic effects across motor systems, consistent with cerebellar involvement. The deletion of exons 1 and 2 is the smallest BCL11A CNV with the full phenotypic expression reported to date. The present results support previous findings in that BCL11A-IDD can result from BCL11A variants regardless of type (deletion, SNVs). A gene expression study shows that BCL11 is expressed highly in the early developing cerebellum and primary motor and auditory cortices. Significant co-expression rates in these regions with genes previously implicated in disorders of spoken language and in ASD support the phenotypic overlaps in children with BCL11A-IDD, CAS, and ASD., (© 2022 Wiley Periodicals LLC.)

AOA2 is a rare progressive adolescent-onset disease characterised by cerebellar vermis atrophy, peripheral neuropathy and elevated serum alpha-fetoprotein (AFP) caused by pathogenic bi-allelic variants in SETX, encoding senataxin, involved in DNA repair and RNA maturation. Sanger sequencing of genomic DNA, co-segregation and oxidative stress functional studies were performed in Family 1. Trio whole-exome sequencing (WES), followed by SETX RNA and qRT-PCR analysis, were performed in Family 2. Sanger sequencing in Family 1 revealed two novel in-frame SETX deletion and duplication variants in trans (c.7009_7011del; p.Val2337del and c.7369_7371dup; p.His2457dup). Patients had increased induced chromosomal aberrations at baseline and following exposure to higher mitomycin-C concentration and increased sensitivity to oxidative stress at the lower mitomycin-C concentration in cell viability test. Trio WES in Family 2 revealed two novel SETX variants in trans, a nonsense variant (c.568C > T; p.Gln190*), and a deep intronic variant (c.5549-107A > G). Intronic variant analysis and SETX mRNA expression revealed activation of a cryptic exon introducing a premature stop codon (p.Met1850Lysfs*18) and resulting in aberrant splicing, as shown by qRT-PCR analysis, thus leading to higher levels of cryptic exon activation. Along with a second deleterious allele, this variant leads to low levels of SETX mRNA and disease manifestations. Our report expands the phenotypic spectrum of AOA2. Results provide initial support for the hypomorphic nature of the novel in-frame deletion and duplication variants in Family 1. Deep-intronic variant analysis of Family 2 variants potentially reveals a previously undescribed poison exon in the SETX gene, which may contribute to tailored therapy development., (© 2022. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Speech and language impairments are commonly reported in DYRK1A syndrome. Yet, speech and language abilities have not been systematically examined in a prospective cohort study. Speech, language, social behaviour, feeding, and non-verbal communication skills were assessed using standardised tools. The broader health and medical phenotype was documented using caregiver questionnaires, interviews and confirmation with medical records. 38 individuals with DYRK1A syndrome (23 male, median age 8 years 3 months, range 1 year 7 months to 25 years) were recruited. Moderate to severe intellectual disability (ID), autism spectrum disorder (ASD), vision, motor and feeding impairments were common, alongside epilepsy in a third of cases. Speech and language was disordered in all participants. Many acquired some degree of verbal communication, yet few (8/38) developed sufficient oral language skills to rely solely on verbal communication. Speech was characterised by severe apraxia and dysarthria in verbal participants, resulting in markedly poor intelligibility. Those with limited verbal language (30/38) used a combination of sign and graphic augmentative and alternative communication (AAC) systems. Language skills were low across expressive, receptive, and written domains. Most had impaired social behaviours (25/29). Restricted and repetitive interests were most impaired, whilst social motivation was a relative strength. Few individuals with DYRK1A syndrome use verbal speech as their sole means of communication, and hence, all individuals need early access to tailored, graphic AAC systems to support their communication. For those who develop verbal speech, targeted therapy for apraxia and dysarthria should be considered to improve intelligibility and, consequently, communication autonomy., (© 2022. The Author(s), under exclusive licence to European Society of Human Genetics.)

Background: Speech is the most common modality through which language is communicated, and delayed, disordered, or absent speech production is a hallmark of many neurodevelopmental and genetic disorders. Yet, speech is not often carefully phenotyped in neurodevelopmental disorders. In this paper, we argue that such deep phenotyping, defined as phenotyping that is specific to speech production and not conflated with language or cognitive ability, is vital if we are to understand how genetic variations affect the brain regions that are associated with spoken language. Speech is distinct from language, though the two are related behaviorally and share neural substrates. We present a brief taxonomy of developmental speech production disorders, with particular emphasis on the motor speech disorders childhood apraxia of speech (a disorder of motor planning) and childhood dysarthria (a set of disorders of motor execution). We review the history of discoveries concerning the KE family, in whom a hereditary form of communication impairment was identified as childhood apraxia of speech and linked to dysfunction in the FOXP2 gene. The story demonstrates how instrumental deep phenotyping of speech production was in this seminal discovery in the genetics of speech and language. There is considerable overlap between the neural substrates associated with speech production and with FOXP2 expression, suggesting that further genes associated with speech dysfunction will also be expressed in similar brain regions. We then show how a biologically accurate computational model of speech production, in combination with detailed information about speech production in children with developmental disorders, can generate testable hypotheses about the nature, genetics, and neurology of speech disorders., Conclusions: Though speech and language are distinct, specific types of developmental speech disorder are associated with far-reaching effects on verbal communication in children with neurodevelopmental disorders. Therefore, detailed speech phenotyping, in collaboration with experts on pediatric speech development and disorders, can lead us to a new generation of discoveries about how speech development is affected in genetic disorders., (© 2022. The Author(s).)

Background: Ataxia with oculomotor apraxia (AOA) is characterized by early-onset cerebellar ataxia associated with oculomotor apraxia. AOA1, AOA2, AOA3, and AOA4 subtypes may present pathogenic variants in APTX, SETX, PIK3R5, and PNKP genes, respectively. Mutations in XRCC1 have been found to cause autosomal recessive spinocerebellar ataxia-26 (SCAR26) now considered AOA5., Objectives: To examine a cohort of Brazilians with autosomal recessive cerebellar ataxia plus oculomotor apraxia and determine the frequencies of AOA subtypes through genetic investigation., Methods: We evaluated clinical, biomarkers, electrophysiological, and radiological findings of 52 patients with AOA phenotype and performed a genetic panel including APTX, SETX, PIK3R5, PNKP, and XRCC1., Results: We found pathogenic variants in SETX (15 patients), PNKP (12), and APTX (5). No mutations in PIK3R5 or XRCC1 were identified., Conclusions: AOA2 and AOA4 were the most common forms of AOA in Brazil. Mutations in PIK3R5 and XRCC1 were not part of this genetic spectrum. © 2022 International Parkinson and Movement Disorder Society., (© 2022 International Parkinson and Movement Disorder Society.)

Hereditary ataxias are a group of devastating neurological disorders that affect coordination of gait and are often associated with poor coordination of hands, speech, and eye movements. Ataxia with ocular apraxia type 1 (AOA1) (OMIM: 606,350.0006) is characterized by slowly progressive symptoms of childhood-onset and pathogenic mutations in APTX; the only known cause underpinning AOA1. APTX encodes the protein aprataxin, composed of three domains sharing homology with proteins involved in DNA damage, signaling, and repair. We present four siblings from an endogamic family in a rural, isolated town of Colombia with ataxia and ocular apraxia of childhood-onset and confirmed molecular diagnosis of AOA1, homozygous for the W279* p.Trp279Ter mutation. We predicted the mutated APTX with AlphaFold to demonstrate the effects of this stop-gain mutation that deletes three beta helices encoded by amino acid 270 to 339 rescinding the C2H2-type zinc fingers (Znf) (C2H2 Znf) DNA-binding, the DNA-repair domain, and the whole 3D structure of APTX. All siblings exhibited different ages of onset (4, 6, 8, and 11 years old) and heterogeneous patterns of dysarthria (ranging from absence to mild-moderate dysarthria). Neuropsychological evaluation showed no neurocognitive impairment in three siblings, but one sibling showed temporospatial disorientation, semantic and phonologic fluency impairment, episodic memory affection, constructional apraxia, moderate anomia, low executive function, and symptoms of depression. To our knowledge, this report represents the most extensive series of siblings affected with AOA1 in Latin America, and the genetic analysis completed adds important knowledge to outline this family's disease and general complex phenotype of hereditary ataxias., (© 2022. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Wieacker-Wolff syndrome is an X-linked condition caused by variants of the ZC4H2 gene that results in in utero muscular weakness that manifests clinically as arthrogryposis congenita as well as facial and bulbar weakness. We report the case of a young girl with a de novo pathogenic deletion in the ZC4H2 gene and clinical features consistent with Wieacker-Wolff syndrome. Common eye manifestations of the syndrome reported in the literature include ptosis, strabismus, and oculomotor apraxia. The overall incidence of these manifestations is 56%., (Copyright © 2022 American Association for Pediatric Ophthalmology and Strabismus. Published by Elsevier Inc. All rights reserved.)

Mutations in the SETX gene, which encodes Senataxin, are associated with the progressive neurodegenerative diseases ataxia with oculomotor apraxia 2 (AOA2) and amyotrophic lateral sclerosis 4 (ALS4). To identify the causal defect in AOA2, patient-derived cells and SETX knockouts (human and mouse) were analyzed using integrated genomic and transcriptomic approaches. A genome-wide increase in chromosome instability (gains and losses) within genes and at chromosome fragile sites was observed, resulting in changes to gene-expression profiles. Transcription stress near promoters correlated with high GCskew and the accumulation of R-loops at promoter-proximal regions, which localized with chromosomal regions where gains and losses were observed. In the absence of Senataxin, the Cockayne syndrome protein CSB was required for the recruitment of the transcription-coupled repair endonucleases (XPG and XPF) and RAD52 recombination protein to target and resolve transcription bubbles containing R-loops, leading to genomic instability. These results show that transcription stress is an important contributor to SETX mutation-associated chromosome fragility and AOA2., Competing Interests: The authors declare no competing interest., (Copyright © 2022 the Author(s). Published by PNAS.)

49,XXXXY is the rarest X and Y chromosomal variation and is frequently characterized by expressive and receptive language dysfunction, low muscle tonus, and intellectual deficits. Due to the low incidence of this disorder, comprehensive studies analyzing the specific aspects of the speech and language phenotype in these boys have been uncommon. This is the first in-depth investigation of the speech and language profiles in a large cohort of boys with 49,XXXXY. Based on the clinical judgment of speech and language pathologists, there was an increased incidence (91.8%) of Childhood Apraxia of Speech (CAS), which has not been previously described in this disorder. In preschool boys, some significant differences were demonstrated between boys who received early hormonal treatment (n = 16) and untreated boys (n = 4) on the language scales (p = .047) on the Bayley Scales of Infants and Toddlers, as well as significant differences between treated (n = 13) and untreated boys (n = 8) on the Expressive One Word Picture Vocabulary Test (p = .008). No significant differences between treatment groups were found in school age children, however, treated groups demonstrated less discrepancies between expressive and receptive language. More research and larger samples are needed to determine the extent of the impact of testosterone treatment on boys with 49,XXXXY. This study identifies CAS as a potential explanation for the significant expressive language dysfunction and subsequent behavioral dysfunction. These findings may assist in facilitating more targeted treatment and improved outcomes for boys with 49,XXXXY., (© 2020 Wiley Periodicals LLC.)

Background : Duane retraction syndrome and arthrogryposis multiplex congenita have an incidence of approximately 1:1500-1:3000 live births. However, the association of these two entities with a Marcus-Gunn might be a rare and, until now, under-recognized clinical presentation of the Wieacker-Wolff Syndrome. Patient and methods : We report a 7-year-old female with dysmorphic features, global developmental delay, arthrogryposis multiplex congenita (AMC), Duane retraction syndrome (DRS), and unilateral Marcus Gunn jaw winking. Results : Whole Exome Sequencing showed a de novo premature stop codon in ZC4H2. Extensive genetic and metabolic work was negative otherwise and Brain MRI showed delayed non-specific myelination abnormalities. She continues to have significant delays but does not have regression, seizures or other neurological complications. She has required a multidisciplinary approach for the management of her multiple contractures. Conclusion : This case confirms ZC4H2 as a cause of syndromic DRS and extends the ZC4H2 phenotype to include Marcus Gunn jaw winking.

Early-onset ataxia with ocular motor apraxia and hypoalbuminemia (EAOH) is a neurodegenerative disorder caused by mutation in the aprataxin (APTX)-coding gene APTX, which is involved in DNA single-strand break repair (SSBR). The neurological abnormalities associated with EAOH are similar to those observed in patients with ataxia-telangiectasia. However, the immunological abnormalities in patients with EAOH have not been described. In this study, we report that EAOH patients have immunological abnormalities, including lymphopenia; decreased levels of CD4 + T-cells, CD8 + T-cells, and B-cells; hypogammaglobulinemia; low T-cell recombination excision circles and kappa-deleting element recombination circles; and oligoclonality of T-cell receptor β-chain variable repertoire. These immunological abnormalities vary among the EAOH patients. Additionally, mild radiosensitivity in the lymphocytes obtained from the patients with EAOH was demonstrated. These findings suggested that the immunological abnormalities and mild radiosensitivity evident in patients with EAOH could be probably caused by the DNA repair defects., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Ataxia with oculomotor apraxia type 2 (AOA2), recently renamed as ATX-SETX, is an autosomal recessive, progressive neurodegenerative disorder belonging to inherited cerebellar ataxias. The pathogenic variants of the SETX gene have been implicated in ATX-SETX. We report the case of a 21-year-old woman presenting with ataxia, oculomotor apraxia and dystonia. She had elevated serum α-fetoprotein (AFP), follicle stimulating hormone (FSH) and luteinising hormone (LH) levels and moderate cerebellar atrophy. On further evaluation, she was found to have premature ovarian failure as well. Multiplex ligation-dependent probe amplification detected a heterozygous deletion in exon 6 of the SETX gene. A combination of cerebellar ataxia, oculomotor apraxia with elevated AFP and cerebellar atrophy are highly suggestive of ATX-SETX. In rare instances, it may be associated with premature ovarian failure with elevated FSH and LH levels, necessitating hormonal survey and fertility evaluation in all patients with ATX-SETX., Competing Interests: Competing interests: None declared., (© BMJ Publishing Group Limited 2021. No commercial re-use. See rights and permissions. Published by BMJ.)

Progressive apraxia of speech is a neurodegenerative syndrome affecting spoken communication. Molecular pathology, biochemistry, genetics, and longitudinal imaging were investigated in 32 autopsy-confirmed patients with progressive apraxia of speech who were followed over 10 years. Corticobasal degeneration and progressive supranuclear palsy (4R-tauopathies) were the most common underlying pathologies. Perceptually distinct speech characteristics, combined with age-at-onset, predicted specific 4R-tauopathy; phonetic subtype and younger age predicted corticobasal degeneration, and prosodic subtype and older age predicted progressive supranuclear palsy. Phonetic and prosodic subtypes showed differing relationships within the cortico-striato-pallido-nigro-luysial network. Biochemical analysis revealed no distinct differences in aggregated 4R-tau while tau H1 haplotype frequency (69%) was lower compared to 1000+ autopsy-confirmed 4R-tauopathies. Corticobasal degeneration patients had faster rates of decline, greater cortical degeneration, and shorter illness duration than progressive supranuclear palsy. These findings help define the pathobiology of progressive apraxia of speech and may have consequences for development of 4R-tau targeting treatment.

Heterozygous pathogenic WAC variants cause Desanto-Shinawi syndrome; affected patients have dysmorphic features, developmental impairment and behavioral abnormalities. Seizures are reported in one quarter, including tonic-clonic, absence, and febrile seizures. This study aimed to better understand the phenotypic spectrum of epilepsy and development in Desanto-Shinawi syndrome. We identified four children with seizures and pathogenic WAC variants, including two siblings. All had global developmental impairment with language affected most severely; two had diagnoses of childhood apraxia of speech and two had autism spectrum disorder. Seizure onset age ranged from six months to 14 years. Seizures always occurred from sleep and were focal impaired awareness with motor features in three patients, with one having bilateral tonic-clonic seizures of suspected focal onset. Two patients had spontaneous seizure resolution without treatment, and the remaining two were well-controlled on monotherapy. EEG was normal in two patients; one had focal right frontal spikes in drowsiness and sleep while the last had independent centrotemporal spikes from both hemispheres, activated in sleep. All patients had heterozygous truncating pathogenic WAC variants, with negative parental testing. The findings in this cohort of patients suggest that epilepsy in Desanto-Shinawi syndrome is usually focal and self-limited, and may fall within the epilepsy-aphasia spectrum., Competing Interests: Declaration of competing interest Dr. Myers reports research funding support from Citizens United for Research in Epilepsy, Savoy Foundation, Dravet Canada, Fonds de recherche du Québec – Santé, and the Research Institute of the McGill University Health Centre; and is a site principal investigator or sub-investigator for trials sponsored by LivaNova and Biogen. Dr Scheffer serves/has served on the editorial boards of the Annals of Neurology, Neurology and Epileptic Disorders; may accrue future revenue on pending patent WO61/010,176 (filed: 2008): Therapeutic Compound; has a patent for SCN1A testing held by Bionomics Inc and licensed to various diagnostic companies; has a patent molecular diagnostic/theranostic target for benign familial infantile epilepsy (BFIE) [PRRT2] 2,011,904,493 & 2,012,900,190 and PCT/AU2012/001321 (TECH ID:2012–009) with royalties paid. She has served on scientific advisory boards for UCB, Eisai, GlaxoSmithKline, BioMarin, Nutricia, Rogcon and Xenon Pharmaceuticals; has received speaker honoraria from GlaxoSmithKline, UCB, BioMarin, Biocodex and Eisai; has received funding for travel from UCB, Biocodex, GlaxoSmithKline, Biomarin and Eisai; has served as an investigator for Zogenix, Zynerba, Ultragenyx, GW Pharma, UCB, Eisai, Anavex Life Science and Marinus; and has consulted for Zynerba Pharmaceuticals, Atheneum Partners, Ovid Therapeutics and UCB. She receives/has received research support from the National Health and Medical Research Council of Australia, Medical Research Future Fund, Health Research Council of New Zealand, CURE, Australian Epilepsy Research Fund, March of Dimes and NIH/NINDS. The remaining authors have no conflicts of interest., (Copyright © 2020 European Paediatric Neurology Society. Published by Elsevier Ltd. All rights reserved.)

Purpose: To investigate the literature for frequencies, profiles and neural correlates of limb and face apraxias in frontotemporal dementia (FTD)., Method: The search conducted in Ovid Medline, PsycINFO and Scopus yielded 487 non-duplicate records, and 43 were included in the final analysis., Results: Apraxias are evident in diverse forms in all clinical variants of FTD within the first four years of the disease. Face apraxia and productive limb apraxia co-occur in the behavioural and nonfluent variants. The logopenic variant resembles Alzheimer's disease in terms of pronounced parietal limb apraxia and absence of face apraxia. The semantic variant exhibits conceptual praxis deficits together with relatively preserved imitation skills. Concerning the genetic variants of FTD, productive limb apraxia is common among carriers of the progranulin gene mutation, and subtle gestural alterations have been documented among carriers of the chromosome 9 open reading frame 72 gene mutation before the expected disease onset. The data on neural correlations suggest that the breakdown of praxis results from bilateral cortical and subcortical damage in FTD and that Alzheimer-type pathology of the cerebrospinal fluid increases the severity of limb apraxia in all of the variants. Face apraxia correlates with degeneration of the medial and superior frontal cortices., Conclusions: Each of the clinical variants of FTD exhibits a characteristic profile of apraxias that may support early differentiation between the variants and from Alzheimer's disease. However, the screening procedures developed for stroke populations seem insufficient, and a multifaceted assessment tool is needed. Although valid and practical tests already exist for dementia populations, a concise selection of test items that covers all of the critical domains is called for., Competing Interests: Declaration of Competing Interest None., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Hereditary mutations in polynucleotide kinase-phosphatase (PNKP) result in a spectrum of neurological pathologies ranging from neurodevelopmental dysfunction in microcephaly with early onset seizures (MCSZ) to neurodegeneration in ataxia oculomotor apraxia-4 (AOA4) and Charcot-Marie-Tooth disease (CMT2B2). Consistent with this, PNKP is implicated in the repair of both DNA single-strand breaks (SSBs) and DNA double-strand breaks (DSBs); lesions that can trigger neurodegeneration and neurodevelopmental dysfunction, respectively. Surprisingly, however, we did not detect a significant defect in DSB repair (DSBR) in primary fibroblasts from PNKP patients spanning the spectrum of PNKP-mutated pathologies. In contrast, the rate of SSB repair (SSBR) is markedly reduced. Moreover, we show that the restoration of SSBR in patient fibroblasts collectively requires both the DNA kinase and DNA phosphatase activities of PNKP, and the fork-head associated (FHA) domain that interacts with the SSBR protein, XRCC1. Notably, however, the two enzymatic activities of PNKP appear to affect different aspects of disease pathology, with reduced DNA phosphatase activity correlating with neurodevelopmental dysfunction and reduced DNA kinase activity correlating with neurodegeneration. In summary, these data implicate reduced rates of SSBR, not DSBR, as the source of both neurodevelopmental and neurodegenerative pathology in PNKP-mutated disease, and the extent and nature of this reduction as the primary determinant of disease severity., (© The Author(s) 2020. Published by Oxford University Press on behalf of Nucleic Acids Research.)

Objective: Determining the genetic basis of speech disorders provides insight into the neurobiology of human communication. Despite intensive investigation over the past 2 decades, the etiology of most speech disorders in children remains unexplained. To test the hypothesis that speech disorders have a genetic etiology, we performed genetic analysis of children with severe speech disorder, specifically childhood apraxia of speech (CAS)., Methods: Precise phenotyping together with research genome or exome analysis were performed on children referred with a primary diagnosis of CAS. Gene coexpression and gene set enrichment analyses were conducted on high-confidence gene candidates., Results: Thirty-four probands ascertained for CAS were studied. In 11/34 (32%) probands, we identified highly plausible pathogenic single nucleotide (n = 10; CDK13 , EBF3 , GNAO1 , GNB1 , DDX3X , MEIS2 , POGZ , SETBP1 , UPF2 , ZNF142 ) or copy number (n = 1; 5q14.3q21.1 locus) variants in novel genes or loci for CAS. Testing of parental DNA was available for 9 probands and confirmed that the variants had arisen de novo. Eight genes encode proteins critical for regulation of gene transcription, and analyses of transcriptomic data found CAS-implicated genes were highly coexpressed in the developing human brain., Conclusion: We identify the likely genetic etiology in 11 patients with CAS and implicate 9 genes for the first time. We find that CAS is often a sporadic monogenic disorder, and highly genetically heterogeneous. Highly penetrant variants implicate shared pathways in broad transcriptional regulation, highlighting the key role of transcriptional regulation in normal speech development. CAS is a distinctive, socially debilitating clinical disorder, and understanding its molecular basis is the first step towards identifying precision medicine approaches., (© 2020 American Academy of Neurology.)

Deletions and duplications involving the CNTN4 gene, which encodes for the contactin 4 protein, have been reported in children with autism spectrum disorder (ASD) and other neurodevelopmental phenotypes. In this study, we performed clinical and genetic characterization of three individuals from unrelated families with copy number variants (CNV) (one deletion and two duplications) within CNTN4. The patients exhibited cognitive delay (3/3), growth restriction (3/3), motor delay (2/3), and febrile seizure/epilepsy (2/3). In contrast to previous reports, all probands presented with speech apraxia or delay with no diagnosis of ASD. Parental studies for the proband with the deletion and one of the 2 probands with the duplication revealed paternal origin of the CNTN4 CNV. Interestingly, previously documented CNV involving this gene were mostly inherited from unaffected fathers, raising questions regarding reduced penetrance and potential parent-of-origin effect. Our findings are compared with previously reported patients and patients in the DECIPHER database. The speech impairment in the three probands suggests a role for CNTN4 in language development. We discuss potential factors contributing to phenotypic heterogeneity and reduced penetrance and attempt to find possible genotype-phenotype correlation. Larger cohorts are needed for comprehensive and unbiased phenotyping and molecular characterization that may lead to better understanding of the underlying mechanisms of reduced penetrance, variable expressivity, and potential parent-of-origin effect of copy number variants encompassing CNTN4., (Copyright © 2019 Elsevier Masson SAS. All rights reserved.)

Background: Wieacker-Wolff syndrome (WWS) is a congenital X-linked neuromuscular disorder, which was firstly reported in 1985. Zinc finger C4H2-type containing (ZC4H2) gene has been found to be associated with the disease pathogenesis. However, the underlying mechanism remains elusive., Methods: Whole-exome sequencing was performed to identify the mutations. Expression plasmids were constructed and cell culture and immune-biochemical assays were used to examine the effects of the mutation., Results: We reported a female patient with classical symptoms of WWS and discovered a novel nonsense heterozygous mutation (p.R67X; c.199C>T) in ZC4H2 gene in the patient but not in her parents. The mutation resulted in a 66 amino-acid truncated ZC4H2 protein. The mutation is located in the key helix domain and it altered the subcellular locations of the mutant ZC4H2 protein. X-chromosome inactivation (XCI) pattern analysis revealed that the XCI ratio of the proband was 22:78., Conclusion: Female heterozygous carriers with nonsense mutation with a truncated ZC4H2 protein could lead to the pathogenesis of Wieacker-Wolff syndrome and our study provides a potential new target for the disease treatment., (© 2019 The Authors. Molecular Genetics & Genomic Medicine published by Wiley Periodicals, Inc.)

In the present study, a novel mutation in the presenilin 1 gene was discovered in an Iraq-native patient with early-onset Alzheimer's disease, who presented with speech impairment and memory decline at age 46 years. Magnetic resonance imaging showed a frontotemporal atrophy. Sanger sequencing identified a heterozygous T to A transversion at position 815 (c.815T>A) in the presenilin 1 gene (PSEN1), resulting in a novel missense mutation at codon 272 from valine to aspartate (V272D). We tested this PSEN1 mutation in vitro and found V272D resulted in an altered Aβ42/40 ratio., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Genetic investigations of people with impaired development of spoken language provide windows into key aspects of human biology. Over 15 years after FOXP2 was identified, most speech and language impairments remain unexplained at the molecular level. We sequenced whole genomes of nineteen unrelated individuals diagnosed with childhood apraxia of speech, a rare disorder enriched for causative mutations of large effect. Where DNA was available from unaffected parents, we discovered de novo mutations, implicating genes, including CHD3, SETD1A and WDR5. In other probands, we identified novel loss-of-function variants affecting KAT6A, SETBP1, ZFHX4, TNRC6B and MKL2, regulatory genes with links to neurodevelopment. Several of the new candidates interact with each other or with known speech-related genes. Moreover, they show significant clustering within a single co-expression module of genes highly expressed during early human brain development. This study highlights gene regulatory pathways in the developing brain that may contribute to acquisition of proficient speech.

Ataxia with oculomotor apraxia type 2 (AOA2) is a rare autosomal recessive neurodegenerative disorder characterized by cerebellar atrophy, peripheral neuropathy and oculomotor apraxia. It is caused by mutations in the SETX gene that encodes senataxin, a ubiquitously expressed protein that mediates processes, including transcription, transcription termination, DNA repair, RNA processing, DNA-RNA hybrid (R-loop) elimination and telomere stability. In mice, senataxin is essential for male germ cell development and fertility through its role in meiotic recombination and sex chromosome inactivation. AOA2 is associated with hypogonadism in women, but there are no reports of hypogonadism or infertility in men. We describe the first case of human male infertility caused by germ cell arrest in a man with AOA2. Our patient has a homozygous mutation in the SETX gene (NC_000009.11:g.135158775dup), which results in a frameshift and premature protein termination (NM_015046.6:c.6422dup, p.[Ser2142Glufs*23]). In accordance with the murine phenotype, testis histology revealed disrupted seminiferous tubules with spermatogonia and primary spermatocytes, but absent spermatids. Collectively, these data support an essential role of senataxin in human spermatogenesis, and provide a compelling case that men with AOA2 should be counselled at diagnosis about the possibility of infertility., (Copyright © 2019 Reproductive Healthcare Ltd. Published by Elsevier Ltd. All rights reserved.)

Purpose of Review: This article reviews two of the primary progressive aphasias (PPAs), disorders characterized by the early and predominant impairment of language, and primary progressive apraxia of speech, a degenerative motor speech disorder that is closely related to PPA. An outline of the history and controversy surrounding how these disorders are classified is provided before the article focuses on each disorder's clinical and imaging features., Recent Findings: Over the past decade, the classification of degenerative speech and language disorders has been refined. Clinical, imaging, and pathologic evidence suggests that primary progressive apraxia of speech is a distinct degenerative disorder. Furthermore, multiple lines of evidence have highlighted issues with nonfluent/agrammatic variant PPA, which complicates the diagnosis, prognosis, and study of this disorder. Semantic variant PPA, while not without controversy, remains one of the most well-defined disorders, with good clinicopathologic correlation., Summary: Accurate classification and diagnosis of these degenerative speech and language disorders is crucial in clinical practice and ongoing research efforts. For nonfluent/agrammatic variant PPA, the authors suggest emphasizing agrammatism as the core inclusion criterion and taking care not to include patients with isolated or predominant apraxia of speech. Isolated apraxia of speech can be the manifestation of a degenerative disease and, based on the different prognosis, should be recognized as distinct from PPA. Finally, it is important to recognize that some patients with semantic dementia, despite sharing the same pathologic associations, may not meet criteria for PPA.

Childhood apraxia of speech (CAS) is a rare disorder of childhood that can leave a watermark of the impacts throughout the lifetime. Since being first described in the 1950s, aetiological insights have been limited. At a neurobiological level, clinical MRI scans fail to reveal overt neural anomalies in individual cases with CAS, although quantitative MRI methods have revealed subtle brain anomalies at a group level. Dramatic insights, however, occurred in the past decade from the discovery of genetic pathways underlying the phenotype. Several single genes and copy number-variant conditions are now associated with CAS either in relative isolation, as in the case of FOXP2 variants, or most typically in association with other neurodevelopmental conditions, such as epilepsy, intellectual disability, motor impairment and autism. CAS requires careful differential diagnosis from other childhood speech disorders, but when a severe and persistent diagnosis is confirmed, a genetic aetiology should increasingly be pursued., (© 2018 Paediatrics and Child Health Division (The Royal Australasian College of Physicians).)

Speech apraxia is a disorder of speech motor planning/programming leading to slow rate, articulatory distortion, and distorted sound substitutions. We describe the clinical profile evolution of a patient presenting with slowly progressive isolated speech apraxia that eventually led to the diagnosis of corticobasal syndrome (CBS), supporting the evidence that this rare speech disorder can be the first presentation of CBS. Moreover, we found a novel variant in MAPT gene, which is hypothesized to be disease-causing mutation. These results underscore the importance of genetic analysis - particularly in selected atypical cases - for in vivo understanding of possible pathophysiological disease process.

Recurrent deletions of a ~600-kb region of 16p11.2 have been associated with a highly penetrant form of childhood apraxia of speech (CAS). Yet prior findings have been based on a small, potentially biased sample using retrospectively collected data. We examine the prevalence of CAS in a larger cohort of individuals with 16p11.2 deletion using a prospectively designed assessment battery. The broader speech and language phenotype associated with carrying this deletion was also examined. 55 participants with 16p11.2 deletion (47 children, 8 adults) underwent deep phenotyping to test for the presence of CAS and other speech and language diagnoses. Standardized tests of oral motor functioning, speech production, language, and non-verbal IQ were conducted. The majority of children (77%) and half of adults (50%) met criteria for CAS. Other speech outcomes were observed including articulation or phonological errors (i.e., phonetic and cognitive-linguistic errors, respectively), dysarthria (i.e., neuromuscular speech disorder), minimal verbal output, and even typical speech in some. Receptive and expressive language impairment was present in 73% and 70% of children, respectively. Co-occurring neurodevelopmental conditions (e.g., autism) and non-verbal IQ did not correlate with the presence of CAS. Findings indicate that CAS is highly prevalent in children with 16p11.2 deletion with symptoms persisting into adulthood for many. Yet CAS occurs in the context of a broader speech and language profile and other neurobehavioral deficits. Further research will elucidate specific genetic and neural pathways leading to speech and language deficits in individuals with 16p11.2 deletions, resulting in more targeted speech therapies addressing etiological pathways.

Importance: Ataxia with oculomotor apraxia type 1 (AOA1) is an autosomal recessive cerebellar ataxia due to mutations in the aprataxin gene (APTX) that is characterized by early-onset cerebellar ataxia, oculomotor apraxia, axonal motor neuropathy, and eventual decrease of albumin serum levels., Objectives: To improve the clinical, biomarker, and molecular delineation of AOA1 and provide genotype-phenotype correlations., Design, Setting, and Participants: This retrospective analysis included the clinical, biological (especially regarding biomarkers of the disease), electrophysiologic, imaging, and molecular data of all patients consecutively diagnosed with AOA1 in a single genetics laboratory from January 1, 2002, through December 31, 2014. Data were analyzed from January 1, 2015, through January 31, 2016., Main Outcomes and Measures: The clinical, biological, and molecular spectrum of AOA1 and genotype-phenotype correlations., Results: The diagnosis of AOA1 was confirmed in 80 patients (46 men [58%] and 34 women [42%]; mean [SD] age at onset, 7.7 [7.4] years) from 51 families, including 57 new (with 8 new mutations) and 23 previously described patients. Elevated levels of α-fetoprotein (AFP) were found in 33 patients (41%); hypoalbuminemia, in 50 (63%). Median AFP level was higher in patients with AOA1 (6.0 ng/mL; range, 1.1-17.0 ng/mL) than in patients without ataxia (3.4 ng/mL; range, 0.8-17.2 ng/mL; P < .01). Decreased albumin levels (ρ = -0.532) and elevated AFP levels (ρ = 0.637) were correlated with disease duration. The p.Trp279* mutation, initially reported as restricted to the Portuguese founder haplotype, was discovered in 53 patients with AOA1 (66%) with broad white racial origins. Oculomotor apraxia was found in 49 patients (61%); polyneuropathy, in 74 (93%); and cerebellar atrophy, in 78 (98%). Oculomotor apraxia correlated with the severity of ataxia and mutation type, being more frequent with deletion or truncating mutations (83%) than with presence of at least 1 missense variant (17%; P < .01). Mean (SD) age at onset was higher for patients with at least 1 missense mutation (17.7 [11.4] vs 5.2 [2.6] years; P < .001)., Conclusions and Relevance: The AFP level, slightly elevated in a substantial fraction of patients, may constitute a new biomarker for AOA1. Oculomotor apraxia may be an optional finding in AOA1 and correlates with more severe disease. The p.Trp279* mutation is the most frequent APTX mutation in the white population. APTX missense mutations may be associated with a milder phenotype.