一个汉族自闭症谱系障碍家系的拷贝数变异分析

目的 对一个中国汉族自闭症谱系障碍(autistic spectrum disorder,ASD)家系进行拷贝数变异(copy number variation,CNV)的分析.方法 该家系共3例患者.建立家系成员EB病毒转染永生化的B淋巴细胞系,并提取基因组进行核型分析与Affymatrix 500k SNP芯片检测,所获结果由Genotyping Console与GeneChip(R)Chromosome Copy Number Analysis Tool软件分析,采用家系中3名正常儿童作为对照,对患者中的拷贝数变异进行分析.结果 核型分析未发现染色体变异情况,而15q11位点在患者中都存在拷贝数变异,其中物理位置为19827281-19998230的片段出现了拷贝数减少,含有OR11K1P、OR4Q1P、OR4H6P、OR4M2、OR4N3P等基因,而另外3条分别为37 kb、1316 kb、37 kb的片段则出现了拷贝数增加,含有LOC388079、LOC441709等基因.结论 位于这一拷贝数变异位点上有OR11K1P、OR4Q1P、OR4H6P、OR4M2等嗅觉受体基因,也有功能未明的LOC388079基因,为自闭症的遗传机理研究提供了新的提示.     

Further evidence of a causal association between AGO1, a critical regulator of microRNA formation,and intellectual disability/autism spectrum disorder

Among the many regulators of microRNA formation, Argonaute 1 (AGO1) plays critical roles in RNA interference, which controls a wide range of biological activities. Recent large-scale genomic studies have identified at least five patients with intellectual disability/autism spectrum disorder who had de novo mutations in AGO1, but detailed clinical information was not available. The recognizable clinical features that are associated with AGO1 mutations remain to be determined. The proposita was a 15-year-old girl with diffuse hypotonia, infrequent seizures, and intellectual disability with an intelligence quotient of 41. She had characteristic facial features consisting of telecanthus, wide nasal bridge with bulbous nasal tip, and a round face with downslanted palpebral fissures. Serial computed tomography scans showed progressive calcification in the globus pallidus that became evident during childhood. A whole exome analysis in trio revealed a de novo heterozygous mutation in AGO1, i.e., c.595G > A p.(Gly199Ser). The distinctive facial features, i.e., telecanthus, wide nasal bridge with bulbous nasal tip, and a round face with downslanted palpebral fissures, closely resembled previously reported patients who had a chromosomal microdeletion encompassing AGO1 locus. The combinatory phenotype of such characteristic facial features and radiographic features, i.e. progressive calcification in the globus pallidus, in the presently reported patient suggest that AGO1 mutations lead to a syndromic form of intellectual disability/autism spectrum disorder. Distinctive facial features with early and progressive calcification in the globus pallidus may be suggestive of the presence of AGO1 mutations.     

Severe jaundice in two children with Kawasaki disease: a possible association with Gilbert syndrome

Kawasaki disease is a systemic vasculitis, mainly encountered in children. It may affect any organ. Acute cholestasis and severe obstructive jaundice is an atypical manifestation of the disease. We herein present two children with Kawasaki disease and severe direct hypebilibirunemia who also were homozygous and heterozygous respectively for the (TA)(7) promoter polymorphism of Gilbert syndrome. Intravenous immunoglobulin was administered to both patients at the acute phase of the disease and the fever remitted within 24 hr following the immunoglobulin administration. Furthermore oral aspirin at a dose of 80-100 mg/kg/24 hr was also given. The first child did not develop any coronary ectasia or aneurysm, whereas dilation of the right coronary artery was identified in the second child, one month after the disease onset. We discuss the possible contribution of Gilbert syndrome to the development of jaundice in our patients.     

A de novo mosaic mutation in SPAST with two novel alternative alleles and chromosomal copy number variant in a boy with spastic paraplegia and autism spectrum disorder

Here we report a 12 year old male with an extreme presentation of spastic paraplegia along with autism and dysmorphisms. Whole exome sequencing identified a predicted pathogenic pair of missense variants in SPAST at the same chromosomal location, each with a different alternative allele, while a chromosome microarray identified a 1.73 Mb paternally inherited copy gain of 1q21.1q21.2 resulting in a blended phenotype of both Spastic paraplegia 4 and 1q21.1 microduplication syndrome. We believe that the extreme phenotype observed is likely caused by the presence of cells which contain only mutant SPAST, but that the viability of the patient is possible due mosaicism of mutant alleles observed in different proportions across tissues.     

2p15-p16.1 microdeletion syndrome: molecular characterization and association of the OTX1 and XPO1 genes with autism spectrum disorders

Reports of unrelated individuals with autism spectrum disorder (ASD) and similar clinical features having overlapping de novo interstitial deletions at 2p15-p16.1 suggest that this region harbors a gene(s) important to the development of autism. We molecularly characterized two such deletions, selecting two genes in this region, exportin 1 (XPO1) and orthodenticle homolog 1 (OTX1) for association studies in three North American cohorts (Autism Spectrum Disorder - Canadian American Research Consortium (ASD-CARC), New York, and Autism Genetic Resource Exchange (AGRE)) and one Italian cohort (Società Italiana per la Ricerca e la Formazione sull'Autismo (SIRFA)) of families with ASD. In XPO1, rs6735330 was associated with autism in all four cohorts (P<0.05), being significant in ASD-CARC cohorts (P-value following false discovery rate correction for multiple testing (P(FDR))=1.29 × 10(-5)), the AGRE cohort (P(FDR)=0.0011) and the combined families (P(FDR)=2.34 × 10(-9)). Similarly, in OTX1, rs2018650 and rs13000344 were associated with autism in ASD-CARC cohorts (P(FDR)=8.65 × 10(-7) and 6.07 × 10(5), respectively), AGRE cohort (P(FDR)=0.0034 and 0.015, respectively) and the combined families (P(FDR)=2.34 × 10(-9) and 0.00017, respectively); associations were marginal or insignificant in the New York and SIRFA cohorts. A significant association (P(FDR)=2.63 × 10(-11)) was found for the rs2018650G-rs13000344C haplotype. The above three SNPs were associated with severity of social interaction and verbal communication deficits and repetitive behaviors (P-values <0.01). No additional deletions were identified following screening of 798 ASD individuals. Our results indicate that deletion 2p15-p16.1 is not commonly associated with idiopathic ASD, but represents a novel contiguous gene syndrome associated with a constellation of phenotypic features (autism, intellectual disability, craniofacial/CNS dysmorphology), and that XPO1 and OXT1 may contribute to ASD in 2p15-p16.1 deletion cases and non-deletion cases of ASD mapping to this chromosome region.     

The ALS/PDC syndrome of Guam: potential biomarkers for an enigmatic disorder

The ALS/parkinsonism-dementia complex of Guam is a long latency disease with a diverse phenotypic expression characteristic of classical ALS, parkinsonism and dementia. It is remarkably similar to a syndrome localized to the Kii Peninsula of Japan. There are as yet no identified pathological features that will clearly distinguish the Guam or Kii ALS/PDC syndrome from other degenerative neurological disorders. At present, ALS/PDC of Guam and the Kii Peninsula can be confirmed only by postmortem examination. The most prominent pathological hallmark is the widespread occurrence of neurofibrillary tangles which express the same balance of 3R and 4R tau that is found in Alzheimer disease. They both show an increased prevalence of a peculiar retinal disorder termed linear retinal pigmentary epitheliopathy. The disorders are both highly familial. Several environmental factors have been proposed but no supportive evidence for an environmental or dietary factor has been found. Genome searches have so far failed to identify causative genes although two single nuclear polymorphisms related to MAPT that increase the risk of the Guam syndrome have been located. The two syndromes are clearly unique, and clues as to their causation could be beneficial in understanding the etiology of similar, but much more prevalent disorders in North America, Europe and Asia. Identification of biomarkers for premortem diagnosis would be helpful in management as well as in revealing the true etiology.     

Splenic smooth-muscle tumors in children with acquired immunodeficiency syndrome: report of two cases of this unusual location with evidence of an association with Epstein-Barr virus

Smooth-muscle neoplasms are rarely located in the spleen. They have been previously reported in five cases of children with human immunodeficiency virus (HIV) infection/acquired immunodeficiency syndrome (AIDS). Two cases of children with HIV infection/AIDS with autopsy and surgical pathology evidence of multiple smooth-muscle neoplasms with splenic involvement are presented. DNA was extracted from histology slides in both cases for analysis for Epstein Barr (EB) virus. In both cases, the presence of EB virus was confirmed. This paper documents two additional cases of the unusual phenomenon of splenic involvement by smooth-muscle neoplasms in the setting of AIDS in childhood and further supports the role of EB virus in the development of these neoplasms. Received: 27 January 1999 / Accepted: 23 August 1999     

A novel truncating variant within exon 7 of KAT6B associated with features of both Say–Barber–Bieseker–Young–Simpson syndrome and genitopatellar syndrome: Further evidence of a continuum in the clinical spectrum of KAT6B‐related disorders

KAT6B sequence variants have been identified in both patients with the Say–Barber–Biesecker–Young–Simpson syndrome (SBBYSS) and in the genitopatellar syndrome (GPS). In SBBYSS, they were reported to affect mostly exons 16–18 of KAT6B, and the predicted mechanism of pathogenesis was haploinsufficiency or a partial loss of protein function. Truncating variants in KAT6B leading to GPS appear to cluster within the proximal portion of exon 18, associated with a dominant‐negative effect of the mutated protein, most likely. Although SBBYSS and GPS have been initially considered allelic disorders with distinctive genetic and clinical features, there is evidence that they represent two ends of a spectrum of conditions referable as KAT6B‐related disorders. We detected a de novo truncating variant within exon 7 of KAT6B in a 8‐year‐old female who presented with mild intellectual disability, facial dysmorphisms highly consistent with SBBYSS, and skeletal anomalies including exostosis, that are usually considered component manifestations of GPS. Following the clinical diagnosis driven by the striking facial phenotype, we analyzed the KAT6B gene by NGS techniques. The present report highlights the pivotal role of clinical genetics in avoiding clear‐cut genotype‐phenotype categories in syndromic forms of intellectual disability. In addition, it further supports the evidence that a continuum exists within the clinical spectrum of KAT6B‐associated disorders.