据一项发表于American Journal of Human Genetics杂志的研究报告，研究人员最近发现TRAPPC9基因与人类的某种智力残疾有关。该杂志上另外两篇研究报告也证实了该发现。
一般智力残疾又称为智力落后(mental retardation)，通常会有某些生理异常的症状表现，而这种由TRAPPC9基因导致的智力异常没有明显的症状，而且这种无典型表现的智力残疾占到全世界智力残疾人群的一半左右，由于这种智力残疾没有明显可识别的生理差异，所以要找到引起这种疾病的基因突变非常困难。
Dr. Vincent课题组对巴基斯坦的一个大家族进行研究，并制出TRAPPC9基因的图谱，该家族中有至少7位成员出现了这种无典型表现的智力残疾。TRAPPC9基因突变体所产生的蛋白质导致细胞正常功能无法发挥。（生物谷Bioon.com）
有关人类智力研究：
BMC Neuroscience：用磁脉冲刺激大脑有助提高智力
PNAS：婴儿智商高低与母乳喂养无关
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生物谷推荐原始出处：
The American Journal of Human Genetics, 11 December 2009 doi:10.1016/j.ajhg.2009.11.009
Identification of Mutations in TRAPPC9, which Encodes the NIK- and IKK-β-Binding Protein, in Nonsyndromic Autosomal-Recessive Mental Retardation
Asif Mir1, 16, Liana Kaufman2, 16, Abdul Noor2, Mahdi M. Motazacker3, Talal Jamil1, Matloob Azam4, Kimia Kahrizi5, Muhammad Arshad Rafiq2, Rosanna Weksberg6, Tanveer Nasr7, 8, Farooq Naeem9, 10, Andreas Tzschach3, Andreas W. Kuss3, Gisele E. Ishak11, Dan Doherty12, H. Hilger Ropers3, A. James Barkovich13, Hossein Najmabadi5, Muhammad Ayub7, 14 and John B. Vincent2, 15, ,
1 Department of Bioscience, COMSATS Institute of Information Technology, Islamabad, Pakistan
2 Neuropsychiatry and Development Lab, Neurogenetics Section, Centre for Addiction and Mental Health, Toronto, ON M5T 1R8, Canada
3 Max Planck Institute for Molecular Genetics, 14195 Berlin, Germany
4 Pakistan Institute of Medical Sciences, Islamabad, Pakistan
5 Genetics Research Center, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran
6 Program in Genetics and Genomic Biology, The Hospital for Sick Children, Toronto, ON M5G 1L7, Canada
7 Mayo Hospital, Lahore 54000, Pakistan
8 Chaudhry Hospital, Gujranwala 52250, Pakistan
9 Community Clinical Sciences, School of Medicine, Southampton University, Southampton SO16 5ST, UK
10 Lahore Institute of Research and Development, Lahore 54000, Pakistan
11 Department of Radiology, Seattle Children's Hospital, University of Washington, Seattle, WA 98105, USA
12 Division of Genetics and Developmental Medicine, Seattle Children's Hospital, University of Washington, Seattle, WA 98105, USA
13 Department of Radiology, University of California, San Francisco, San Francisco, CA 94143, USA
14 St. Luke's Hospital, Middlesborough TS4 3AF, UK
15 Department of Psychiatry, University of Toronto, Toronto, ON M5T 1R8, Canada
Mental retardation/intellectual disability is a devastating neurodevelopmental disorder with serious impact on affected individuals and their families, as well as on health and social services. It occurs with a prevalence of ～2%, is an etiologically heterogeneous condition, and is frequently the result of genetic aberrations. Autosomal-recessive forms of nonsyndromic MR (NS-ARMR) are believed to be common, yet only five genes have been identified. We have used homozygosity mapping to search for the gene responsible for NS-ARMR in a large Pakistani pedigree. Using Affymetrix 5.0 single nucleotide polymorphism (SNP) microarrays, we identified a 3.2 Mb region on 8q24 with a continuous run of 606 homozygous SNPs shared among all affected members of the family. Additional genotype data from microsatellite markers verified this, allowing us to calculate a two-point LOD score of 5.18. Within this region, we identified a truncating homozygous mutation, R475X, in exon 7 of the gene TRAPPC9. In a second large NS-ARMR/ID family, previously linked to 8q24 in a study of Iranian families, we identified a 4 bp deletion within exon 14 of TRAPPC9, also segregating with the phenotype and truncating the protein. This gene encodes NIK- and IKK-β-binding protein (NIBP), which is involved in the NF-κB signaling pathway and directly interacts with IKK-β and MAP3K14. Brain magnetic resonance imaging of affected individuals indicates the presence of mild cerebral white matter hypoplasia. Microcephaly is present in some but not all affected individuals. Thus, to our knowledge, this is the sixth gene for NS-ARMR to be discovered.
