目的:对1例产前B超提示骨骼系统发育异常,疑似宫内生长受限的胎儿进行基因检测及生物信息学分析以明确其致病原因。方法:采集胎儿羊水及父母外周血,提取基因组DNA,利用高通量测序平台进行家系全外显子组测序(whole exome sequencing,WES...目的:对1例产前B超提示骨骼系统发育异常,疑似宫内生长受限的胎儿进行基因检测及生物信息学分析以明确其致病原因。方法:采集胎儿羊水及父母外周血,提取基因组DNA,利用高通量测序平台进行家系全外显子组测序(whole exome sequencing,WES)及拷贝数变异测序(copy number variation sequencing,CNV-seq)技术检测,可疑结果经Sanger测序进行验证。结果:胎儿高迁移率族蛋白A2(high mobility group protein AT-Hook-2,HMGA2)基因存在c.223C>T(p.R75W)新发变异,导致氨基酸改变为p.R75W(p.Arg75Trp),为错义突变。根据美国医学遗传学与基因组学学会(American College of Medical Genetics and Genomics,ACMG)指南评级,该变异判定为可能致病性(likely pathogenic):PS2+PM2_Supporting+PP3+PS4_Supporting。根据其临床表型,该胎儿被确诊为常染色体显性遗传的Silver-Russell综合征5型(Silver-Russell syndrome 5,SRS5)。Sanger测序确证了其变异的真实性。结论:HMGA2基因的c.223C>T(p.R75W)杂合致病性变异可能是SRS5的遗传学致病原因,扩充了该基因的变异谱,同时为该胎儿的产前遗传咨询和后续的干预措施提供了理论依据。展开更多
Silver-Russell综合征（silver russell syndrome,SRS）是一组临床和遗传异质性疾病,以小于胎龄儿和（或）生后持续矮小、颅面畸形、肢体不对称伴四肢细为主要临床表现,先天性小指侧弯为特征.该病主要由7号染色体及染色体11p15区域母源...Silver-Russell综合征（silver russell syndrome,SRS）是一组临床和遗传异质性疾病,以小于胎龄儿和（或）生后持续矮小、颅面畸形、肢体不对称伴四肢细为主要临床表现,先天性小指侧弯为特征.该病主要由7号染色体及染色体11p15区域母源或父源性印迹基因表达缺陷所致.国内仅见几例临床报道,本文总结分析1例SRS患儿的临床特点并结合文献复习,旨在提高对SRS的临床及基因的认识.展开更多
BACKGROUND Nonallelic homologous recombination(NAHR)of segmental duplications or low copy repeats(LCRs)result in DNA gain/loss and play an important role in the origin of genomic disorders.CASE SUMMARY A 3-year-old bo...BACKGROUND Nonallelic homologous recombination(NAHR)of segmental duplications or low copy repeats(LCRs)result in DNA gain/loss and play an important role in the origin of genomic disorders.CASE SUMMARY A 3-year-old boy was referred for genetic analysis.Comparative genomic hybrid-ization array analysis revealed a loss of 3776 kb in the 4p16.3 chromosomal region and a gain of 3201 kb in the 11p15.5p15.4 chromosomal region.CONCLUSION Genomic imbalances caused by NAHR in LCRs result in deletion and duplication syndromes.展开更多
BACKGROUND Cyclin-dependent kinase inhibitor 1C(CDKN1C)is a cell proliferation inhibitor that regulates the cell cycle and cell growth through G1 cell cycle arrest.CDKN1C mutations can lead to IMAGe syndrome(CDKN1C al...BACKGROUND Cyclin-dependent kinase inhibitor 1C(CDKN1C)is a cell proliferation inhibitor that regulates the cell cycle and cell growth through G1 cell cycle arrest.CDKN1C mutations can lead to IMAGe syndrome(CDKN1C allele gain-of-function mutations lead to intrauterine growth restriction,metaphyseal dysplasia,adrenal hypoplasia congenital,and genitourinary malformations).We present a Silver-Russell syndrome(SRS)pedigree that was due to a missense mutation affecting the same amino acid position,279,in the CDKN1C gene,resulting in the amino acid substitution p.Arg279His(c.836G>A).The affected family members had an SRS phenotype but did not have limb asymmetry or adrenal insufficiency.The amino acid changes in this specific region were located in a narrow functional region that contained mutations previously associated with IMAGe syndrome.In familial SRS patients,the PCNA region of CDKN1C should be analysed.Adrenal insufficiency should be excluded in all patients with functional CDKN1C variants.CASE SUMMARY We describe the case of an 8-year-old girl who initially presented with short stature.Her height was 91.6 cm,and her weight was 10.2 kg.Physical examination revealed that she had a relatively large head,an inverted triangular face,a protruding forehead,a low ear position,sunken eye sockets,and irregular cracked teeth but no limb asymmetry.Family history:The girl’s mother,greatgrandmother,and grandmother’s brother also had a prominent forehead,triangular face,and severely proportional dwarfism but no limb asymmetry or adrenal insufficiency.Exome sequencing of the girl revealed a new heterozygous CDKN1C(NM_000076.2)c.836G>A mutation,resulting in a variant with a predicted evolutionarily highly conserved arginine substituted by histidine(p.Arg279His).The same causative mutation was found in both the proband’s mother,great-grandmother,and grandmother’s brother,who had similar phenotypes.Thus far,we found an SRS pedigree,which was due to a missense mutation affecting the same amino acid position,279,in the CDKN1C gene,resulting in the amino acid substitution p.Arg279His(c.836G>A).Although the SRS-related CDKN1C mutation is in the IMAGe-related mutation hotspot region[the proliferating cell nuclear antigen(PCNA)domain],no adrenal insufficiency was reported in this SRS pedigree.The reason may be that the location of the genomic mutation and the type of missense mutation determines the phenotype.The proband was treated with recombinant human growth hormone(rhGH).After 1 year of rhGH treatment,the height standard deviation score of the proband increased by 0.93 standard deviation score,and her growth rate was 8.1 cm/year.No adverse reactions,such as abnormal blood glucose,were found.CONCLUSION Functional mutations in CDKN1C can lead to familial SRS without limb asymmetry,and some patients may have glucose abnormalities.In familial SRS patients,the PCNA region of CDKN1C should be analysed.Adrenal insufficiency should be excluded in all patients with functional CDKN1C variants.展开更多
文摘目的:对1例产前B超提示骨骼系统发育异常,疑似宫内生长受限的胎儿进行基因检测及生物信息学分析以明确其致病原因。方法:采集胎儿羊水及父母外周血,提取基因组DNA,利用高通量测序平台进行家系全外显子组测序(whole exome sequencing,WES)及拷贝数变异测序(copy number variation sequencing,CNV-seq)技术检测,可疑结果经Sanger测序进行验证。结果:胎儿高迁移率族蛋白A2(high mobility group protein AT-Hook-2,HMGA2)基因存在c.223C>T(p.R75W)新发变异,导致氨基酸改变为p.R75W(p.Arg75Trp),为错义突变。根据美国医学遗传学与基因组学学会(American College of Medical Genetics and Genomics,ACMG)指南评级,该变异判定为可能致病性(likely pathogenic):PS2+PM2_Supporting+PP3+PS4_Supporting。根据其临床表型,该胎儿被确诊为常染色体显性遗传的Silver-Russell综合征5型(Silver-Russell syndrome 5,SRS5)。Sanger测序确证了其变异的真实性。结论:HMGA2基因的c.223C>T(p.R75W)杂合致病性变异可能是SRS5的遗传学致病原因,扩充了该基因的变异谱,同时为该胎儿的产前遗传咨询和后续的干预措施提供了理论依据。
文摘Silver-Russell综合征（silver russell syndrome,SRS）是一组临床和遗传异质性疾病,以小于胎龄儿和（或）生后持续矮小、颅面畸形、肢体不对称伴四肢细为主要临床表现,先天性小指侧弯为特征.该病主要由7号染色体及染色体11p15区域母源或父源性印迹基因表达缺陷所致.国内仅见几例临床报道,本文总结分析1例SRS患儿的临床特点并结合文献复习,旨在提高对SRS的临床及基因的认识.
文摘BACKGROUND Nonallelic homologous recombination(NAHR)of segmental duplications or low copy repeats(LCRs)result in DNA gain/loss and play an important role in the origin of genomic disorders.CASE SUMMARY A 3-year-old boy was referred for genetic analysis.Comparative genomic hybrid-ization array analysis revealed a loss of 3776 kb in the 4p16.3 chromosomal region and a gain of 3201 kb in the 11p15.5p15.4 chromosomal region.CONCLUSION Genomic imbalances caused by NAHR in LCRs result in deletion and duplication syndromes.
基金Supported by the China Foundation for International Medical Exchange,Pediatric Endocrinology Young and Middle-Aged Doctors’Growth Research Fund,No.Z-2019-41-2101-01.
文摘BACKGROUND Cyclin-dependent kinase inhibitor 1C(CDKN1C)is a cell proliferation inhibitor that regulates the cell cycle and cell growth through G1 cell cycle arrest.CDKN1C mutations can lead to IMAGe syndrome(CDKN1C allele gain-of-function mutations lead to intrauterine growth restriction,metaphyseal dysplasia,adrenal hypoplasia congenital,and genitourinary malformations).We present a Silver-Russell syndrome(SRS)pedigree that was due to a missense mutation affecting the same amino acid position,279,in the CDKN1C gene,resulting in the amino acid substitution p.Arg279His(c.836G>A).The affected family members had an SRS phenotype but did not have limb asymmetry or adrenal insufficiency.The amino acid changes in this specific region were located in a narrow functional region that contained mutations previously associated with IMAGe syndrome.In familial SRS patients,the PCNA region of CDKN1C should be analysed.Adrenal insufficiency should be excluded in all patients with functional CDKN1C variants.CASE SUMMARY We describe the case of an 8-year-old girl who initially presented with short stature.Her height was 91.6 cm,and her weight was 10.2 kg.Physical examination revealed that she had a relatively large head,an inverted triangular face,a protruding forehead,a low ear position,sunken eye sockets,and irregular cracked teeth but no limb asymmetry.Family history:The girl’s mother,greatgrandmother,and grandmother’s brother also had a prominent forehead,triangular face,and severely proportional dwarfism but no limb asymmetry or adrenal insufficiency.Exome sequencing of the girl revealed a new heterozygous CDKN1C(NM_000076.2)c.836G>A mutation,resulting in a variant with a predicted evolutionarily highly conserved arginine substituted by histidine(p.Arg279His).The same causative mutation was found in both the proband’s mother,great-grandmother,and grandmother’s brother,who had similar phenotypes.Thus far,we found an SRS pedigree,which was due to a missense mutation affecting the same amino acid position,279,in the CDKN1C gene,resulting in the amino acid substitution p.Arg279His(c.836G>A).Although the SRS-related CDKN1C mutation is in the IMAGe-related mutation hotspot region[the proliferating cell nuclear antigen(PCNA)domain],no adrenal insufficiency was reported in this SRS pedigree.The reason may be that the location of the genomic mutation and the type of missense mutation determines the phenotype.The proband was treated with recombinant human growth hormone(rhGH).After 1 year of rhGH treatment,the height standard deviation score of the proband increased by 0.93 standard deviation score,and her growth rate was 8.1 cm/year.No adverse reactions,such as abnormal blood glucose,were found.CONCLUSION Functional mutations in CDKN1C can lead to familial SRS without limb asymmetry,and some patients may have glucose abnormalities.In familial SRS patients,the PCNA region of CDKN1C should be analysed.Adrenal insufficiency should be excluded in all patients with functional CDKN1C variants.
