假假性甲状旁腺功能减退症 1b 患者的高通量分子分析揭示了新的遗传和表观遗传缺陷。

High-throughput Molecular Analysis of Pseudohypoparathyroidism 1b Patients Reveals Novel Genetic and Epigenetic Defects.

机构信息

Division of Endocrinology and Diabetes, and The Children's Hospital of Philadelphia and Department of Pediatrics, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA.

Center for Applied Genomics, The Children's Hospital of Philadelphia and Department of Pediatrics, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA.

出版信息

J Clin Endocrinol Metab. 2021 Oct 21;106(11):e4603-e4620. doi: 10.1210/clinem/dgab460.

DOI:10.1210/clinem/dgab460

PMID:34157100

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC8677598/

Abstract

CONTEXT

Patients with pseudohypoparathyroidism type 1b (PHP1b) show disordered imprinting of the maternal GNAS allele or paternal uniparental disomy (UPD). Genetic deletions in STX16 or in upstream exons of GNAS are present in many familial but not sporadic cases.

OBJECTIVE

Characterization of epigenetic and genetic defects in patients with PHP1b.

DESIGN AND PATIENTS

DNA from 84 subjects, including 26 subjects with sporadic PHP1b, 27 affected subjects and 17 unaffected and/or obligate gene carriers from 12 PHP1b families, 11 healthy individuals, and 3 subjects with PHP1a was subjected to quantitative pyrosequencing of GNAS differentially methylated regions (DMRs), microarray analysis, and microsatellite haplotype analysis.

SETTING

Academic medical center.

MAIN OUTCOME MEASUREMENTS

Molecular pathology of PHP1b.

RESULTS

Healthy subjects, unaffected family members and obligate carriers of paternal PHP1b alleles, and subjects with PHP1a showed normal methylation of all DMRs. All PHP1b subjects showed loss of methylation (LOM) at the exon A/B DMR. Affected members of 9 PHP1b kindreds showed LOM only at the exon A/B DMR, which was associated with a 3-kb deletion of STX16 exons 4 through 6 in 7 families and a novel deletion of STX16 and adjacent NEPEPL1 in 1 family. A novel NESP deletion was found in 1 of 2 other families with more extensive methylation defects. One sporadic PHP1b had UPD of 20q, 2 had 3-kb STX16 deletions, and 5 had apparent epigenetic mosaicism.

CONCLUSIONS

We found diverse patterns of defective methylation and identified novel or previously known mutations in 9 of 12 PHP1b families.

摘要

背景

假性甲状旁腺功能减退症 1b 型（PHP1b）患者表现为母源性 GNAS 等位基因印迹紊乱或父源性单亲二倍体（UPD）。许多家族性病例存在 STX16 或 GNAS 上游外显子的基因缺失，但散发性病例不存在。

目的

研究 PHP1b 患者的表观遗传学和遗传学缺陷。

设计和患者

对 84 名受试者的 DNA 进行了研究，包括 26 名散发性 PHP1b 患者、27 名受影响的受试者、12 个 PHP1b 家系的 17 名未受影响的和/或必需基因携带者、11 名健康个体和 3 名 PHP1a 患者。采用定量焦磷酸测序法检测 GNAS 差异甲基化区域（DMR）、微阵列分析和微卫星单体型分析。

地点

学术医疗中心。

主要观察指标

PHP1b 的分子病理学。

结果

健康受试者、未受影响的家族成员和父系 PHP1b 等位基因的必需携带者，以及 PHP1a 患者的所有 DMR 均表现出正常的甲基化。所有 PHP1b 患者的exon A/B DMR 均出现去甲基化（LOM）。9 个 PHP1b 家系的受累成员仅在 exon A/B DMR 出现 LOM，这与 7 个家系的 STX16 外显子 4 至 6 的 3kb 缺失和 1 个家系的 STX16 和相邻 NEPEPL1 的新缺失相关。在另外 2 个具有更广泛甲基化缺陷的家系中发现了 1 个新的 NESP 缺失。2 例散发性 PHP1b 患者存在 20q 的 UPD，2 例存在 3kb 的 STX16 缺失，5 例存在明显的表观遗传镶嵌现象。