Vitamin D Receptor Polymorphisms Associated with Autism Spectrum Disorder.

Vitamin D is endowed with a number of biological properties, including down-regulation of inflammation, and might contribute to the pathogenesis of autism spectrum disorders (ASD). Vitamin D binds to the vitamin D Receptor (VDR); the biological activity of the ensuing complex depends on VDR FokI, BsmI, ApaI, and TaqI gene polymorphisms. We evaluated such Single Nucletoide Polymorphismsm (SNPs) in a cohort of 100 Italian families with ASD children. FokI genotype distribution was skewed in ASD children compared with their healthy sibs (Pc = 0.03 2 df) and to a group of 170 Italian healthy women (HC) (Pc = 0.04 2 df). FokI genotype and allelic distribution skewing were also observed in mothers of ASD children compared to HC (Pc = 0.04 2 df). Both Transmission Disequilibrium Test for single loci and haplotype analysis distribution revealed a major FokI (C) allele-mediated protective effect, which was more frequently transmitted (73%) than not transmitted to healthy sibs (P = 0.02). A protective FokI-, BsmI-, ApaI-, and TaqI (CCAG) haplotype was more frequently carried by healthy sibs than by ASD children (P = 1 × 10-4 ; OR: 0.1, 95% CI: 0.03-0.4) too. Finally, a strong gene-dose association of FokI (T) allele with both higher Childhood Autism Rating Scale score (Pc = 0.01) and, particularly, with hyperactivity behavior (Pc = 0.006) emerged in ASD children. Because the protein produced by the FokI (T) allele is transcriptionally less active than that produced by the FokI (C) allele, the reduced biological activity of the vitamin D/VDR complex prevalent in ASD could favor ASD- and maternal immune activation- associated inflammation. Vitamin D supplementation might be useful in preventative and rehabilitation protocols for ASD. Autism Res 2020, 13: 680-690. © 2020 International Society for Autism Research, Wiley Periodicals, Inc. LAY SUMMARY: Vitamin D deficiency and Vitamin D receptor (VDR) polymorphisms are associated with structural and functional brain abnormalities and behavioral disorders. We analyzed the association of VDR gene polymorphisms in a cohort of 100 Italian families with ASD children. A strong correlation between one of the VDR polymorphisms and hyperactivity behavior was evidenced in ASD children. In healthy mothers, the same VDR polymorphism was also correlated with an increased risk of giving birth to children with ASD.

Predictors of Outcomes in Adolescents With Clinical High Risk for Psychosis, Other Psychiatric Symptoms, and Psychosis: A Longitudinal Protocol Study.

In children and adolescents, schizophrenia is one of the ten main causes of disability-adjusted life years. The identification of people at Clinical High Risk of developing Psychosis (CHR-P) is one of the most promising strategies to improve outcomes. However, in children and adolescents research on the CHR-P state is still in its infancy and the clinical validity of at-risk criteria appears understudied in this population. Furthermore, only few studies have evaluated the psychopathological, neuropsychological, neuroimaging characteristics and, especially, long-term outcomes of adolescents at high risk. We present here the protocol of an innovative longitudinal cohort study of adolescents aged 12-17. The sample will consist of patients admitted to a third level neuropsychiatric unit, belonging to one of the following three subgroups: 1) adolescents with established Diagnostic and Statistical Manual of Mental Disorder-Fifth Edition psychosis, 2) adolescents with CHR-P, and 3) adolescents with psychiatric symptoms other than established psychosis or CHR-P. The primary aim of our study is to evaluate the 2-year prognosis across the three groups. We will measure transition to psychosis (or the stability of the diagnosis of psychosis in the psychotic group), the risk of development of other psychiatric disorders, as well as socio-occupational functioning at outcome. The secondary aim will be to explore the effect of specific predictors (clinical, neuropsychological and neuroimaging factors) on the prognosis. At baseline, 1-year and 2-year follow-up participants will be assessed using standardized semi-structured interviews and instruments. Psychopathological and functioning variables, as well as neuropsychological domains will be compared across the three subgroups. Moreover, at baseline and 2-year follow-up all recruited patients will undergo a 3-Tesla magnetic resonance imaging examination and diffusion tensor imaging parameters will be analyzed. We believe that this study will advance our ability to predict outcomes in underage CHR-P samples. In particular, our data will enable a better understanding of the clinical significance of CHR-P in adolescents, and shed new light on prognostic factors that can be used to refine the prediction of clinical outcomes and the implementation of preventive interventions.

HLA-G coding region polymorphism is skewed in autistic spectrum disorders.

Different isoforms of HLA-G protein are endowed with a differential ability to induce allogenic tolerance during pregnancy. As prenatal immune activation is suggested to play a role in the onset of autistic spectrum disorders (ASD), we evaluated HLA G*01:01-*01:06 allelic polymorphism in a cohort of Italian children affected by ASD (N=111) their mothers (N=81), and their healthy siblings (N=39). DNA sequencing analysis of HLA-G exon 2, 3 and 4 was used to obtain HLA-G allelic frequencies; alleles distribution was compared with that of two control groups of Caucasoid couples of multiparous women and their partners from Brazil and Denmark. HLA-G distribution was significantly different in ASD children compared to both control groups (Brazilian pc=1×10-4; Danish pc=1×10-3). Since HLA-G distribution was similar in the two control groups, their data were pooled. Results indicated that HLA-G*01:01 was significantly less frequent (pc=1×10-4; OR:0.5, 95%CI: 0.3-0.7) whereas HLA-G*01:05N was significantly more frequent (pc=2×10-3; OR:7.3, 95%CI: 2.4-26.6) in ASD children compared to combined controls. Finally, no clear pattern emerged when HLA-G allelic distribution was analyzed in healthy sibs. Notably, HLA-G allelic distribution found in ASD mothers was similar to that observed in the control subgroup of women with recurrent miscarriages, whilst it was significantly different compared to women without miscarriages (pc=6×10-4 df=12). Since HLA-G*01:01 is associated with the elicitation of KIR-mediated tolerogenic responses and HLA-G*01:05N correlates with NK cells activation, results herein indicate that an immune activating milieu during pregnancy is more likely observed in association with the development of ASD, similarly to what occurs in women with recurrent miscarriages.

HLA-G∗14bp Insertion and the KIR2DS1-HLAC2 Complex Impact on Behavioral Impairment in Children with Autism Spectrum Disorders.

Activating KIR-HLA-C ligand complexes and HLA-G∗14bp insertion/deletion (+/-) polymorphism were associated to Autism Spectrum Disorders (ASD) and were suggested to correlate with inflammation during fetal development. We evaluated whether HLA-G∗14bp(+/-) and KIR-HLA-C complexes are associated with cognitive and behavioral scores and EEG profile in 119 ASD children (58 from Sardinia, 61 from Peninsular Italy). KIR2DS1-C2; KIR2DS2-C1; KIR2DL1-C2; KIR2DL2-C1; KIR2DL3-C1 and HLA-G∗14bp(+/-) were molecularly genotyped by Single Specific Primer PCR and gel electrophoresis. Univariate linear model analysis adjusted for age, gender and provenience showed statistically higher scores of Childhood Autism Rating Scale (CARS) and Autistic Core Behavior in KIR2DS1-C2+/HLA-G∗14bp+ASD children (43.7±1.5, p=0.03; 3.3±0.1, p=0.03, respectively). These results suggested a synergistic polygenic association of KIR2DS1-HLAC2+/HLA-G∗14bp+ pattern with behavioral impairment in ASD children.