8p23.2-pter Microdeletions: Seven New Cases Narrowing the Candidate Region and Review of the Literature.

To date only five patients with 8p23.2-pter microdeletions manifesting a mild-to-moderate cognitive impairment and/or developmental delay, dysmorphisms and neurobehavioral issues were reported. The smallest microdeletion described by Wu in 2010 suggested a critical region (CR) of 2.1 Mb including several genes, out of which FBXO25, DLGAP2, CLN8, ARHGEF10 and MYOM2 are the main candidates. Here we present seven additional patients with 8p23.2-pter microdeletions, ranging from 71.79 kb to 4.55 Mb. The review of five previously reported and nine Decipher patients confirmed the association of the CR with a variable clinical phenotype characterized by intellectual disability/developmental delay, including language and speech delay and/or motor impairment, behavioral anomalies, autism spectrum disorder, dysmorphisms, microcephaly, fingers/toes anomalies and epilepsy. Genotype analysis allowed to narrow down the 8p23.3 candidate region which includes only DLGAP2, CLN8 and ARHGEF10 genes, accounting for the main signs of the broad clinical phenotype associated to 8p23.2-pter microdeletions. This region is more restricted compared to the previously proposed CR. Overall, our data favor the hypothesis that DLGAP2 is the actual strongest candidate for neurodevelopmental/behavioral phenotypes. Additional patients will be necessary to validate the pathogenic role of DLGAP2 and better define how the two contiguous genes, ARHGEF10 and CLN8, might contribute to the clinical phenotype.

A Regional ADHD Center-Based Network Project for the Diagnosis and Treatment of Children and Adolescents With ADHD.

OBJECTIVE: We aimed to define the sociodemographic, clinical, and prescription profiles of the participants enrolled in the Italian Lombardy ADHD Register. METHOD: Data on patients evaluated by the 18 regional ADHD reference centers in the 2012 to 2013 period were analyzed. RESULTS: Seven hundred fifty-three of 1,150 (65%) suspected patients received a diagnosis of ADHD. In 24% of cases, there was a family history of ADHD. Four hundred eighty-three (64%) patients had at least one psychopathological disorder, the more common of which were learning disorders (35%). Eighty-four percent of patients received a prescription for psychoeducational interventions, 2% received only pharmacological treatment, and 14% a combination of both. Compared with patients treated with psychoeducational intervention alone, patients with drug prescriptions more commonly presented values of Clinical Global Impressions - Severity scale (CGI-S) of 5 or higher ( p < .0001). CONCLUSION: A continuous and systematic monitoring of patterns of care is essential in promoting significant improvements in clinical practice and ensuring an efficient and homogeneous quality of care.

Autism spectrum disorder in tuberous sclerosis complex: searching for risk markers.

BACKGROUND: Neuropsychiatric disorders are present in up to 90% of patients with Tuberous Sclerosis Complex (TSC), and represent an important issue for families. Autism Spectrum Disorder (ASD) is the most common neurobehavioral disease, affecting up to 61% of patients. The aims of this study were: 1) to assess the prevalence of ASD in a TSC population; 2) to describe the severity of ASD; 3) to identify potential risk factors associated with the development of ASD in TSC patients. METHODS: We selected 42 individuals over age 4 years with a definite diagnosis of TSC and followed at a TSC clinic in Northern Italy. We collected and reported clinical and genetic data, as well as cognitive level, for each of them. We administered the Social Communication Questionnaire (SCQ) as a reliable screening tool for ASD, and performed comparisons between the average scores and each clinical and genetic feature. RESULTS: Seventeen out of 42 patients (40.5%) had a score at the SCQ suggestive of ASD (≥15 points). When calculated for each cognitive level category, the average SCQ score tended to be progressively higher in patients with a worse cognitive level, and the number of pathological SCQ scores increased with worsening of intellectual disability. With respect to ASD severity, the scores were equally distributed, indicating that the degree of ASD in TSC patients may have a large variability. By comparing the average SCQ scores with the clinical features, we found statistically significant correlations with epilepsy, seizure onset before age one year, spasms, mutations in TSC2, cognitive level, sleep disorders, and other psychiatric problems, but not with seizure frequency, tubers localization and gender. CONCLUSIONS: Our study showed a prevalence of ASD of 40.5%, confirming the higher risk for this disorder in patients with TSC. However, the severity seems to have a notable variability in TSC patients. Risk factors for ASD are epilepsy, infantile spams, and mutations in TSC2.

Cluster analysis of autistic patients based on principal pathogenetic components.

We have recently described four principal pathogenetic components in autism: (I) circadian and sensory dysfunction, (II) immune abnormalities, (III) neurodevelopmental delay, and (IV) stereotypic behaviors. Using hierarchical and k-means clustering, the same 245 patients assessed in our principal component analysis can be partitioned into four clusters: (a) 43 (17.6%) have prominent immune abnormalities accompanied by some circadian and sensory issues; (b) 44 (18.0%) display major circadian and sensory dysfunction, with little or no immune symptoms; (c) stereotypies predominate in 75 (31.0%); and (d) 83 (33.9%) show a mixture of all four components, with greater disruptive behaviors and mental retardation. The "immune" component provides the largest contributions to phenotypic variance (P = 2.7 x 10(-45)), followed by "stereotypic behaviors." These patient clusters may likely differ in genetic and immune underpinnings, developmental trajectories, and response to treatment.

Urinary p-cresol is elevated in small children with severe autism spectrum disorder.

Several studies have described in autistic patients an overgrowth of unusual gut bacterial strains, able to push the fermentation of tyrosine up to the formation of p-cresol. We compared levels of urinary p-cresol, measured by high-performance liquid chromatography-ultraviolet, in 59 matched case-control pairs. Urinary p-cresol was significantly elevated in autistic children smaller than 8 years of age (p < 0.01), typically females (p < 0.05), and more severely affected regardless of sex (p < 0.05). Urinary cotinine measurements excluded smoking-related hydrocarbon contaminations as contributors to these differences. Hence, elevated urinary p-cresol may serve as a biomarker of autism liability in small children, especially females and more severely affected males.

Family-based association study of ITGB3 in autism spectrum disorder and its endophenotypes.

The integrin-ß 3 gene (ITGB3), located on human chromosome 17q21.3, was previously identified as a quantitative trait locus (QTL) for 5-HT blood levels and has been implicated as a candidate gene for autism spectrum disorder (ASD). We performed a family-based association study in 281 simplex and 12 multiplex Caucasian families. ITGB3 haplotypes are significantly associated with autism (HBAT, global P=0.038). Haplotype H3 is largely over-transmitted to the affected offspring and doubles the risk of an ASD diagnosis (HBAT P=0.005; odds ratio (OR)=2.000), at the expense of haplotype H1, which is under-transmitted (HBAT P=0.018; OR=0.725). These two common haplotypes differ only at rs12603582 located in intron 11, which reaches a P-value of 0.072 in single-marker FBAT analyses. Interestingly, rs12603582 is strongly associated with pre-term delivery in our ASD patients (P=0.008). On the other hand, it is SNP rs2317385, located at the 5' end of the gene, that significantly affects 5-HT blood levels (Mann-Whitney U-test, P=0.001; multiple regression analysis, P=0.010). No gene-gene interaction between ITGB3 and SLC6A4 has been detected. In conclusion, we identify a significant association between a common ITGB3 haplotype and ASD. Distinct markers, located toward the 5' and 3' ends of the gene, seemingly modulate 5-HT blood levels and autism liability, respectively. Our results also raise interest into ITGB3 influences on feto-maternal immune interactions in autism.

Principal pathogenetic components and biological endophenotypes in autism spectrum disorders.

Autism is a complex neurodevelopmental disorder, likely encompassing multiple pathogenetic components. The aim of this study is to begin identifying at least some of these components and to assess their association with biological endophenotypes. To address this issue, we recruited 245 Italian patients with idiopathic autism spectrum disorders and their first-degree relatives. Using a stepwise approach, patient and family history variables were analyzed using principal component analysis ("exploratory phase"), followed by intra- and inter-component cross-correlation analyses ("follow-up phase"), and by testing for association between each component and biological endophenotypes, namely head circumference, serotonin blood levels, and global urinary peptide excretion rates ("biological correlation phase"). Four independent components were identified, namely "circadian & sensory dysfunction," "immune dysfunction," "neurodevelopmental delay," and "stereotypic behavior," together representing 74.5% of phenotypic variance in our sample. Marker variables in the latter three components are positively associated with macrocephaly, global peptiduria, and serotonin blood levels, respectively. These four components point toward at least four processes associated with autism, namely (I) a disruption of the circadian cycle associated with behavioral and sensory abnormalities, (II) dysreactive immune processes, surprisingly linked both to prenatal obstetric complications and to excessive postnatal body growth rates, (III) a generalized developmental delay, and (IV) an abnormal neural circuitry underlying stereotypies and early social behaviors.

Candidate gene study of HOXB1 in autism spectrum disorder.

BACKGROUND: HOXB1 plays a major role in brainstem morphogenesis and could partly determine the cranial circumference in conjunction with HOXA1. In our sample, HOXA1 alleles significantly influence head growth rates both in autistic patients and in population controls. An initial report, suggesting that HOXB1 could confer autism vulnerability in interaction with HOXA1, was not confirmed by five small association studies. METHODS: Our sample includes 269 autistic individuals, belonging to 219 simplex and 28 multiplex families. A mutational analysis of the two exons and flanking intronic sequences of the HOXB1 gene was carried out in 84 autistic patients by denaturing high performance liquid chromatography, followed by DNA sequencing. Identified rare variants were then searched by a restriction analysis in 236 autistic patients and 325-345 controls. Case-control and family-based association studies were performed on two common variants in 169 Italian patients versus 184 Italian controls and in 247 trios. RESULTS: We identified three common polymorphisms, rs72338773 [c.82insACAGCGCCC (INS/nINS)], rs12939811 [c.309A>T (Q103H)], and rs7207109 [c.450G>A (A150A)] and three rare variants, namely IVS1+63G>A, rs35115415 [c.702G>A (V234V)] and c.872_873delinsAA (S291N). SNPs rs72338773 and rs12939811 were not associated with autism, using either a case-control (alleles, exact P = 0.13) or a family-based design [transmission/disequilibrium test (TDT)chi2 = 1.774, P = 0.183]. The rare variants, all inherited from one of the parents, were present in two Italian and in two Caucasian-American families. Autistic probands in two families surprisingly inherited a distinct rare variant from each parent. The IVS1+63A allele was present in 3/690 control chromosomes, whereas rare alleles at rs35115415 and c.872_873delinsAA (S291N) were not found in 662 and 650 control chromosomes, respectively. The INS-T309 allele influenced head size, but its effect appears more modest and shows no interaction with HOXA1 alleles. The INS-T309 allele is also associated with more severe stereotypic behaviours, according to ADI-R scores (N = 60 patients, P < 0.01). CONCLUSIONS: HOXB1 mutations do not represent a common cause of autism, nor do HOXB1 common variants play important roles in autism vulnerability. HOXB1 provides minor, albeit detectable contributions to head circumference in autistic patients, with HOXA1 displaying more prominent effects. HOXB1 variants may modulate the clinical phenotype, especially in the area of stereotypic behaviours.

Clinical, morphological, and biochemical correlates of head circumference in autism.

BACKGROUND: Head growth rates are often accelerated in autism. This study is aimed at defining the clinical, morphological, and biochemical correlates of head circumference in autistic patients. METHODS: Fronto-occipital head circumference was measured in 241 nonsyndromic autistic patients, 3 to 16 years old, diagnosed according to DSM-IV criteria. We assessed 1) clinical parameters using the Autism Diagnostic Observation Schedule, Autism Diagnostic Interview-Revised, Vineland Adaptive Behavioral Scales, intelligence quotient measures, and an ad hoc clinical history questionnaire; 2) height and weight; 3) serotonin (5-HT) blood levels and peptiduria. RESULTS: The distribution of cranial circumference is significantly skewed toward larger head sizes (p < .00001). Macrocephaly (i.e., head circumference >97th percentile) is generally part of a broader macrosomic endophenotype, characterized by highly significant correlations between head circumference, weight, and height (p < .001). A head circumference >75th percentile is associated with more impaired adaptive behaviors and with less impairment in IQ measures and motor and verbal language development. Surprisingly, larger head sizes are significantly associated with a positive history of allergic/immune disorders both in the patient and in his/her first-degree relatives. CONCLUSIONS: Our study demonstrates the existence of a macrosomic endophenotype in autism and points toward pathogenetic links with immune dysfunctions that we speculate either lead to or are associated with increased cell cycle progression and/or decreased apoptosis.

Autistic disorder associated with congenital HIV infection.

Although autistic disorder is rare, we identified three children with this syndrome in a sample of 286 children with congenital HIV infection. The prevalence of autistic disorder was thus greater than expected from epidemiological data. The present article describes the clinical manifestations and course of development of the three children. Etiologic heterogeneity in autism is assumed by most investigators because of the occurrence of autistic disorder in persons with a variety of other disorders (e. g. viral or genetic). We hypothesize that there is a complex relation between congenital HIV infection and austistic disorder and suggest the need for systematic investigations of larger series of HIV positive children.