■智力残疾的遗传形式(ID),在一般人群中,估计患病率在1%到3%之间,是医疗保健中最重要的问题之一。尤其是,常染色体隐性遗传ID具有非常异质的分子基础,并且缺乏特定的表型特征。
■这里,我们报道了两名不相关的常染色体隐性遗传ID患者,小头畸形,和自闭症特征,并回顾TRAPPC9相关ID的患者。进行全外显子组测序和阵列CGH的分子诊断。
■第一种情况在染色体8q24.23-q24.3区域上有一个微缺失,长度为1.7Mb,包括TRAPPC9的最后5个外显子和c.3435delG[p。Thr1146Profs*8]删除。第二种情况具有纯合错义c.623A>C(p。通过先证者的全外显子组测序研究检测到的TRAPPC9中的His208Pro)变体。我们还回顾了迄今为止报道的所有TRAPPC9相关ID患者的临床表现和突变谱。
■我们的研究表明,与TRAPPC9相关的ID最一致的临床发现是ID,小头畸形,和一些脑MRI结构异常。TRAPPC9中的突变散布在TRAPPC9的所有外显子中,表明该基因中没有热点突变区域。
UNASSIGNED: Hereditary forms of intellectual disability (ID), an estimated prevalence ranging between 1% and 3% in the general population, are among the most important problems in health care. Especially, autosomal-recessive ID has a very heterogeneous molecular basis and a lack of specific phenotypic features.
UNASSIGNED: Here, we report on two unrelated patients with autosomal-recessive ID, microcephaly, and autistic features and
review the patients with
TRAPPC9-related ID. Whole-exome sequencing and array CGH were performed for molecular diagnosis of the patients.
UNASSIGNED: The first case has a microdeletion on chromosome 8q24.23-q24.3 region which is 1.7 Mb in length and includes the last 5 exons of TRAPPC9, and c.3435delG [p.Thr1146Profs*8] deletion. The second case has a homozygous missense c.623A>C (p.His208Pro) variant in
TRAPPC9 which is detected by means of whole-exome sequencing study of the proband. We also reviewed the clinical findings and mutation spectrum of all patients with
TRAPPC9-related ID reported so far.
UNASSIGNED: Our study showed that the most consistent clinical findings for TRAPPC9-related ID are ID, microcephaly, and some structural brain MRI abnormalities. The mutations in the
TRAPPC9 are scattered throughout all exons of
TRAPPC9 indicating there is no hot spot mutation region in this gene.