The autism "epidemic": Ethical, legal, and social issues in a developmental spectrum disorder.

Classic autism has gradually evolved into the concept of a larger "spectrum disorder." The rising prevalence of autism and autism spectrum disorder (autism/ASD) diagnoses can be largely attributed to broader diagnostic criteria, adoption of dimensional assessment strategies, increased awareness, linking of services to diagnosis, and the inclusion of milder neurodevelopmental differences bordering on normality. The spectrum disorder diagnosis raises numerous bioethical issues for individuals and society. Three groups of caregivers have important ethical, legal, and social obligations to individuals with autism/ASD: (1) families and advocates of individuals with autism/ASD; (2) health care and other professionals; and (3) governments. Each group may have different views of autism/ASD diagnostic criteria, screening, testing, and the effectiveness of various interventions. All see timely diagnosis as desirable, but earlier diagnosis may not be better, morally or practically. The growing practice of genetic testing in milder ASD raises ethical questions because of its uncertain scientific validity and limited clinical utility. Individuals with autism/ASD have various kinds of needs but all want acceptance and most deserve better accommodations. Governments struggle to provide a fair allocation of appropriate special education and supportive services. This article examines the evolving dimensions of the autism/ASD diagnosis, outlines certain bioethics principles related to its evaluation and management, reviews relevant laws and disability rights, and emphasizes the societal obligation to recognize neurodevelopmental variation and human neurodiversity. Future directions in the evaluation and care of autism/ASD should attempt to integrate the roles and responsibilities of all agents caring for each unique autistic individual.

Dyscalculia and the Calculating Brain.

Dyscalculia, like dyslexia, affects some 5% of school-age children but has received much less investigative attention. In two thirds of affected children, dyscalculia is associated with another developmental disorder like dyslexia, attention-deficit disorder, anxiety disorder, visual and spatial disorder, or cultural deprivation. Infants, primates, some birds, and other animals are born with the innate ability, called subitizing, to tell at a glance whether small sets of scattered dots or other items differ by one or more item. This nonverbal approximate number system extends mostly to single digit sets as visual discrimination drops logarithmically to "many" with increasing numerosity (size effect) and crowding (distance effect). Preschoolers need several years and specific teaching to learn verbal names and visual symbols for numbers and school agers to understand their cardinality and ordinality and the invariance of their sequence (arithmetic number line) that enables calculation. This arithmetic linear line differs drastically from the nonlinear approximate number system mental number line that parallels the individual number-tuned neurons in the intraparietal sulcus in monkeys and overlying scalp distribution of discrete functional magnetic resonance imaging activations by number tasks in man. Calculation is a complex skill that activates both visual and spatial and visual and verbal networks. It is less strongly left lateralized than language, with approximate number system activation somewhat more right sided and exact number and arithmetic activation more left sided. Maturation and increasing number skill decrease associated widespread non-numerical brain activations that persist in some individuals with dyscalculia, which has no single, universal neurological cause or underlying mechanism in all affected individuals.

Autism Spectrum Disorders (ASD) in Blind Children: Very High Prevalence, Potentially Better Outlook.

Autism spectrum disorders affected 19 of 38 unselected children at a school for the blind in Cordoba, Argentina. Autism was linked to total congenital blindness, not blindness' etiology, acquired or incomplete blindness, sex, overt brain damage, or socioeconomic status. Autism "recovery," had occurred in 4 verbal children. Congenital blindness causes profoundly deviant sensory experience and massive reorganization of brain connectivity. Its ≥ 30 times greater prevalence than in sighted children suggests a distinct pathogenesis. Unawareness of autism's high prevalence in blind individuals includes blindness' rarity, misunderstanding of autism as "disease" rather than dimensional behavioral diagnosis, reluctance to diagnose it in blind children, and ignorance of its potentially more favorable outcome. Future investigation may suggest interventions to prevent or mitigate it.

Classification of behaviorally defined disorders: biology versus the DSM.

Three levels of investigation underlie all biologically based attempts at classification of behaviorally defined developmental and psychiatric disorders: Level A, pseudo-categorical classification of mostly dimensional descriptions of behaviors and their disorders included in the 2013 American Psychiatric Association's Fifth Edition of the Diagnostic and Statistical Manual (DSM-5); Level C, mostly categorical classification of genetic and environmental causes (etiologies) of Level A disorders; and Level B, the pathophysiologic--both categorical and dimensional--biologic mechanisms underlying Level A "diagnoses" which comprise hierarchically interacting molecular, cellular, and neural networks and major brain pathways orchestrated by Level C etiologies. Besides modest numbers of effective psychotropic medications and their derivatives, major advances in treatment have addressed the behavioral symptoms of Level A-defined developmental and psychiatric disorders. The National Institute of Mental Health proposes support for a new biologically based Research Domain Criteria (RDoC) classification; its goal is to apply to behaviorally defined Level A developmental and psychiatric disorders the biologically based Level C and Level B research strategies that have greatly accelerated treatment and prevention of medical disorders. It plans to supplement effective educational and behavioral symptom-based interventions with faster, more potent and specific biologic therapies and, hopefully, to discover how effective behavioral interventions alter brain function. This commentary raises the question of whether a hybrid nosology that maps biology onto behavior is attainable. At a minimum, such a nosologic effort requires greater in-depth and better informed dialog between investigators of behavior and biology than occurs typically, and more realistic communication of the implications of research results to the public.

Abnormalities of joint mobility and gait in children with autism spectrum disorders.

AIMS: Abnormalities of gross motor function in children with autism are well known to clinicians but have not received much empirical documentation and, with the exception of stereotypies, are not among its diagnostic criteria. We recorded the characteristics of gait and prevalence of toe walking, the range of passive joint mobility, and age at walking in children with DSM IV autism spectrum disorders (ASDs) and in age- and gender-matched typically developing peers (mean age 4years 6months, range 22months-10years 9months). METHODS: We evaluated maximum range of mobility at the elbow, wrist, metacarpo-phalangeal, and ankle joints and videoed children walking and running. Two neurologists blind to diagnosis independently scored features of gait clinically. RESULTS: Children with ASDs had significantly greater joint mobility (p<.002), more gait abnormalities (p<.0001), and on average walked 1.6months later than their non-autistic peers. INTERPRETATION: This study indicates that attention should be directed to motor abnormalities as well as sociability, communication, and restricted and repetitive behaviors in individuals with ASDs. Motor deficits add to children's other handicaps. They indicate that ASDs affect a broader range of central nervous system circuitry than often appreciated.

Motor stereotypies and volumetric brain alterations in children with Autistic Disorder.

Motor stereotypies are defined as patterned, repetitive, purposeless movements. These stigmatizing motor behaviors represent one manifestation of the third core criterion for an Autistic Disorder (AD) diagnosis, and are becoming viewed as potential early markers of autism. Moreover, motor stereotypies might be a tangible expression of the underlying neurobiology of this neurodevelopmental disorder. In this study, we videoscored stereotypies recorded during semi-structured play sessions from school age children with AD. We examined the effect of severity and persistence over time of stereotypies on brain volumetric changes. Our findings confirmed that the brain volume of school age children with AD is, on average, larger than that of age-matched typically developing children. However, we have failed to detect any sign of volumetric differences in brain regions thought to be particularly linked to the pathophysiology of stereotypies. This negative finding may suggest that, at least with respect to motor stereotypies, functional rather than structural alterations might be the underpinning of these disruptive motor manifestations of autism.

Disorders of nucleotide excision repair.

Deficient repair of ubiquitous errors in the genome risks faulty transcription or replication. Its direct and indirect phenotypic consequences are rare, complex, dementing, lethal disorders of children with inadequately understood overlapping genotypes and variable severity. Mutations of CSA or CSB responsible for impaired transcription-coupled repair cause Cockayne syndrome (CS). Its characteristics are (1) profound growth deficiency affecting all tissues, including the brain, (2) premature aging marked by cachexia, vascular disease, exocrine deficiency, and osteopenia, but not cancer, and (3) a selective degenerative disorder of central and peripheral myelin and by neuronal loss in the retina and inner ear, and in the cerebellum and basal ganglia where it is associated with calcification. Xeroderma pigmentosum (XP) can arise from mutations of at least eight genes involved in global genomic repair. Severe XPA and XPC cause innumerable carcinomas and melanomas in light-exposed eyes and skin, and enhanced risk of visceral cancers. XPA and XPD and others can cause childhood XP neurological disease with widespread neuronal loss, axonal sensorimotor neuropathy, and dwarfing. Four genes, including XPD, can cause trichothiodystrophy (TTD) with sulfur-deficient, brittle, tiger-tail hair, and growth and developmental inadequacy. CSB or XPD can cause the severe congenital cerebro-oculofacioskeletal (COFS) CS-like syndrome with joint contractures, cataracts, and early death. Three XP genes can also cause XP/CS complex. Much more needs to be learned about these and other disorders of DNA repair to enable prevention and treatment.

Neurobiological basis of autism.

Autism (autism spectrum disorders) is a complex, strongly genetically influenced, behaviorally defined disorder of the immature brain associated with very uneven intellectual abilities. Among its most salient and potentially treatable neurologic features that this article focuses on are epilepsy, disorganized sleep patterns, and sensory and motor deficits. Its many causes and wide range of severity means that there is no symptom, no pathology, imaging, electroencephalography, or other biologic feature, and no biologic treatment that is universal or diagnostic of this developmental syndrome.

CEP41 is mutated in Joubert syndrome and is required for tubulin glutamylation at the cilium.

Tubulin glutamylation is a post-translational modification that occurs predominantly in the ciliary axoneme and has been suggested to be important for ciliary function. However, its relationship to disorders of the primary cilium, termed ciliopathies, has not been explored. Here we mapped a new locus for Joubert syndrome (JBTS), which we have designated as JBTS15, and identified causative mutations in CEP41, which encodes a 41-kDa centrosomal protein. We show that CEP41 is localized to the basal body and primary cilia, and regulates ciliary entry of TTLL6, an evolutionarily conserved polyglutamylase enzyme. Depletion of CEP41 causes ciliopathy-related phenotypes in zebrafish and mice and results in glutamylation defects in the ciliary axoneme. Our data identify CEP41 mutations as a cause of JBTS and implicate tubulin post-translational modification in the pathogenesis of human ciliary dysfunction.

Brief report: life history and neuropathology of a gifted man with Asperger syndrome.

Despite recent interest in the pathogenesis of the autism spectrum disorders (pervasive developmental disorders), neuropathological descriptions of brains of individuals with well documented clinical information and without potentially confounding symptomatology are exceptionally rare. Asperger syndrome differs from classic autism by lack of cognitive impairment or delay in expressive language acquisition. We examined the 1,570 g brain of a 63 year old otherwise healthy mathematician with an Autistic Spectrum Disorder of Asperger subtype. Except for an atypical gyral pattern and megalencephaly, we detected no specific neuropathologic abnormality. Taken together, the behavioral data and pathological findings in this case are compatible with an early neurodevelopmental process affecting multiple neuroanatomic networks, but without a convincing morphologic signature detectable with routine neuropathologic technology.

Child neurologists as evaluators of developmental disorders.

Child neurologists are required to evaluate and care for an increasing number of children with developmental disorders; therefore they need to be familiar with the more prevalent ones, in particular the autism spectrum disorders which may masquerade as others. Their assessment needs to include a screening mental status evaluation and reviewing a recent definitive test of hearing in all children with defective speech. Neurologists' responsibility is to make sure that there is no likely underlying problem like epilepsy, neurologic, or genetic condition that requires specific medical intervention or genetic counseling. They need to discuss with the parents how deeply to test for neurologic, neuropsychologic, or genetic underlying causes in children with "idiopathic" developmental problem. There is no routine work-up, thus neurologists need to be aware of and to protect children from many almost certainly uninformative, expensive tests like EEGs, brain imaging, metabolic tests, and genetic micro-array unless there is a specific indication, or testing is being performed with parents' consent for research and paid for by research, not clinical, funds. Child neurologists-in-training need to have observed psychologic/neuropsychologic testing so that they have at least a superficial understanding of the content, indications, and limitations of major tests. I do not recommend that child neurologists administer standardized tests or questionnaires, but they need to know enough about them to be able to judge their appropriateness and review recommendations with parents. Neurologists need to protect children from unnecessary testing, ineffective and in some cases potentially dangerous exploitative treatments. They must be aware of what legitimate therapies are likely to be offered, that early appropriate education is most effective long-term because it influences brain development and is superior to symptomatic pharmacotherapy. If pills are needed, child psychiatrists are likely to be better informed than neurologists and need to be consulted whenever medications familiar to neurologists are not adequately effective.

Male predominance in autism: neuroendocrine influences on arousal and social anxiety.

We offer a neurobiologic theory based on animal work that helps account for the conspicuous male predominance in autism spectrum disorders (ASD). In young male animals, testosterone (TST) binds to androgen receptors (AR) in brainstem neurons responsible for enhancing brain arousal. As a consequence, arousal-related neurotransmitters bombard the amygdala hypersensitized by TST acting though AR. Arousal-related inputs are known to prime amygdaloid mechanisms for fear and anxiety, with resultant social avoidance. We hypothesize that similar mechanisms contribute to autism's male predominance and to its defining impaired social skills. The theory rests on two key interacting factors: the molecular effects of TST in genetically vulnerable boys in combination with environmental stresses they experienced in utero, neonatally, or during the first years. We postulate that higher TST levels and, therefore, higher amounts of arousal-related inputs to the amygdala sensitize these genetically vulnerable male infants to very early stresses. In sharp contrast to boys, girls not only do not have high levels of TST-facilitated arousal-causing inputs to the amygdala but they also enjoy the protection afforded by estrogenic hormones, oxytocin, and the oxytocin receptor. This theory suggests that novel technologies applied to the molecular endocrinology of TST's actions through AR will offer new avenues of enquiry into ASD. Since the high male preponderance in autism is important yet understudied, we offer our theory, which is based on detailed neurobehavioral research with animals, to stimulate basic and clinical research in animals and humans and hopefully help develop novel more effective medical treatments for autism.

Neuropathology of Cockayne syndrome: Evidence for impaired development, premature aging, and neurodegeneration.

Global growth and development failure, premature, accelerated, pathologic aging, and neurodegeneration characterize Cockayne syndrome (CS) and the cerebro-oculo-facial-skeletal and xeroderma pigmentosum/CS syndromes which overlap CS partially in their genetic, somatic, and neuropathologic features. Mutations of CSA or CSB genes jeopardize transcription-coupled repair of damaged nuclear and mitochondrial DNA and resumption of replication and transcription. Resultant defective proteins or gene silencing eventuate in profound dwarfism and micrencephaly, cachexia, vasculopathy, and neurodegeneration. Cellular effects are highly selective. Purkinje cells may die by apoptosis and have grossly dystrophic dendrites. Neuronal death and axonal spheroids indexing neuronal pathology predominate in, but are not limited to, the cerebellum. Progressive loss of retinal, cochlear, and vestibular sensory receptors foster degeneration of ganglion cells and transneuronal brain degeneration. Some proliferating astrocytes are multinucleated and bizarre. Primary damage of oligodendrocytes and Schwann cells may - or may not - explain severe patchy myelin loss ("tigroid leukodystrophy") and segmental demyelinating peripheral neuropathy. Age-related changes are minor in the brain, although precocious severe athero- and arteriolosclerosis are responsible for occasional strokes. Vasculopathology may contribute to myelin loss and to dystrophic mineralization of neurons and vessels, especially in basal ganglia and cerebellum. Understanding the genetics, biochemical, and cellular pathophysiology of these disorders remains fragmentary.

Subtypes of language disorders in school-age children with autism.

Cluster analysis of test scores on expressive phonology and comprehension of words and sentences in 7-9-year-old children with preschool diagnosis of Autistic Disorder yielded 4 clusters. Cluster 1 (N = 11): phonology and comprehension both low; Cluster 2 (N = 4): phonology low, near average comprehension; Cluster 3 (N = 40): average phonology, comprehension low to low average; Cluster 4 (N = 7): average or better phonology and comprehension. The clusters support two major types of language disorders in autism driven by impaired expressive phonology, each divisible by comprehension ability. The clusters refute a single language disorder in autism and are consonant with earlier-defined clinical subtypes.