A deep intronic mutation in AR gene causing androgen insensitivity syndrome: difficulties of diagnostics

Partial androgen resistance syndrome (PAIS) is the most difficult form of disorders/differences of sex development 46,XY (DSD 46,XY) for choosing of patient management. To date, there are no clear biochemical criteria, especially before puberty, that allow differentiating PAIS from other PAIS-like forms of DSD 46, XY, and genetic verification of the partial form of AIS plays an important role. Meanwhile, according to the literature, mutations in the coding region of AR gene have not been identified in more than 50% of patients with suspected AIS. We performed an extensive analysis of the AR gene in a patient with clinical and laboratory signs of AIS and found a deep intron mutation in the AR gene (p. 2450–42G>A). This variant creates an alternative splice acceptor site resulted a disturbance of the AR function. These findings indicate the need for extensive genetic analysis in a cohort of patients with suspected CPA in the absence of mutations in the AR gene using standard methods of genetic diagnosis.

A second hit somatic (p.R905W) and a novel germline intron-mutation of TSC2 gene is found in intestinal lymphangioleiomyomatosis: a case report with literature review

Background Tuberous sclerosis complex (TSC) is an autosomal dominant disorder characterized by hamartomas in multiple organs associated with germline mutations in TSC1 and TSC2, including exonic, intronic, or mosaic mutations. Gastrointestinal (GI) tract Lymphangioleiomyomatosis (LAM) is an extremely rare manifestation of TSC, with few reported cases. Herein, we aimed to determine the driver mutation, pathogenesis, and relationship of germline and somatic mutations of LAM through whole-genome sequencing (WGS) of the tumor and blood samples and whole transcriptome sequencing (WTS) analysis. Case presentation A nine-year-old girl with a full-blown TSC presented with abdominal masses detected during a routine check-up. Resected intestinal masses were diagnosed as LAM by thorough pathological examination. Interestingly, the LAM presented a somatic TSC2 gene mutation in exon 24 (p.R905W, c.C2713T), and the patient had intron retention by a novel germline mutation in the intron region of TSC2 (chr16:2126489, C > G). Conclusion Our case suggests that intron retention by a single nucleotide intronic mutation of TSC2 is sufficient to develop severe manifestations of TSC, but the development of LAM requires an additional somatic oncogenic mutation of TSC2.

Sitosterolemia With Atherosclerosis in a Child: A Case Report

Introduction: Sitosterolemia is a rare condition in children and is often misdiagnosed as familial hypercholesterolemia. Serious complications can result if not treated promptly and effectively. When pediatric patients are diagnosed with sitosterolemia, vascular, and cardiac studies are important to evaluate for the presence of atherosclerosis. Few cases of severe atherosclerotic heart disease in children with sitosterolemia have been reported, making this case worthy of presentation.Case Presentation: Here, we report a case of sitosterolemia in an 8-year-old child. The patient presented with severe hypercholesterolemia and xanthoma. He was diagnosed two and a half years prior with familial hypercholesterolemia because his father had elevated cholesterol levels. After conventional treatment, the patient was dissatisfied with lipid level control and visited our hospital for further management. Genetic tests of the patient and parents found mutations in intron 7 (NM 022436.2, c.904+1G>A) and intron 9 (NM 022436.2, C. 1324+1de1G) of ABCG5. The 7 intron mutation was from his mother, and the 9 intron mutation was from his father. The patient was diagnosed with sitosterolemia.Results: The child was treated with ezetimibe, a low plant sterol diet, and clopidogrel anticoagulant therapy. After 3 months of treatment, the blood lipid level was significantly lower.Conclusion: Genetic testing should be completed as soon as possible to avoid misdiagnosis in children with abnormally elevated hypercholesterolemia who have a family history of elevated cholesterol. In addition, clinicians should rule out great arterial lesions and be vigilant in evaluating patients for systemic arterial disease and atherosclerosis.

A Second Hit Somatic (P.R905W) and a Novel Germline Intron-Mutation of TSC2 Gene is Found in Intestinal Lymphangioleiomyomatosis: A Case Report with Literature Review

Background: Tuberous sclerosis complex (TSC) is an autosomal dominant disorder associated with germline mutations in TSC1 and TSC2, including exonic, intronic, or mosaic mutations. Gastrointestinal (GI) tract Lymphangioleiomyomatosis (LAM) is an extremely rare manifestation of TSC, with few reported cases. Herein, we aimed to determine the driver mutation, pathogenesis, and relationship of germline and somatic mutations of LAM through whole-genome sequencing (WGS) of the tumor and blood samples and whole transcriptome sequencing (WTS) analysis. Case presentation: A nine-year-old girl with a full-blown TSC presented with abdominal masses detected during a routine check-up. Resected intestinal masses were diagnosed as LAM by thorough pathological examination. Interestingly, the LAM presented a somatic TSC2 gene mutation in exon 24 (p.R905W, c.C2713T), and the patient had intron retention by a novel germline mutation in the intron region of TSC2 (chr16:2126489, C>G). Conclusion: Our case suggests that intron retention by a single nucleotide intronic mutation of TSC2 is sufficient to develop severe manifestations of TSC, but the development of LAM requires an additional somatic oncogenic mutation.

A novel intron mutation in FBN-1 gene identified in a pregnant woman with Marfan syndrome

Marfan syndrome (MFS) is one of the most common hereditary connective tissue diseases, with great individual heterogeneity. We reported a Chinese pregnancy with Clinical diagnosis of MFS, performed whole-exome sequencing, and screened for the genetic abnormality. We also conducted an in vitro mini-gene splicing assay to demonstrate the predicted harmful effects of an intronic variant of FBN-1. Exome sequencing identified a novel intronic variant (c.6497-13 T>A) in intron 53 of the FBN-1 gene (NM_000138.4). It’s predicted to insert 11 bp of intron 53 into the mature mRNA. The mini-gene splicing experiment demonstrated that c.6497-13 T>A could result in 11 bp retention in intron 53 to exon 54 (c.6496_6497ins gtttcttgcag) and the use of an alternative donor causing the frameshift p.Asp2166Glyfs*23. According to the results, the pregnant woman chose to continue the pregnancy and gave birth to a healthy baby. This study expands the genetic mutation spectrum of MFS patients and indicates the importance of intron sequencing.

Multiple Endocrine Neoplasia Type 1: A Chinese Family with a New Germline Mutation(c.201delC) and Detection Errors Due to an Intron Mutation

Background: Multiple endocrine neoplasia type 1 (MEN1) is a hereditary cancer syndrome caused by germline mutations in the MEN1 gene located on chromosome 11q13. The three main endocrine tissues affected most frequently by tumors in MEN1 are the parathyroid (95%), enteropancreatic neuroendocrine tissues (50%), and anterior pituitary (40%). The purpose of this study was to report on a Chinese family with a new heterozygous MEN1 mutation in exon 2 [NM_130802: c.201delC (p.Ala68Profs*51) with localization to Chr11:64577381 on assembly GRCh37]. Methods: A 49-year-old female patient (proband) was admitted to the hospital due to intermittent recurrent hypoglycemia symptoms. After a series of examinations, we found that she had a pancreatic tumor, parathyroid tumor, adrenal tumor, and suspicious gastrinoma. Due to the proband’s suspicious clinical manifestations of MEN1, we performed genetic detection for the proband and her immediate family members. We also used multiplex ligation-dependent probe amplification (MLPA) to rule out homozygous mutations caused by a deletion of gene fragments in the proband and her immediate family members. Results: A new MEN1 germline mutation [c.201delC (p.Ala68Profs*51)], which could induce MEN1, was found by the genetic test. Two of the proband’s six relatives were found by the genetic test to have the same mutations as the proband, and the proband’s sister also had the typical symptoms of MEN1. However, the first and second genetic detection results showed that they were homozygous mutations, which did not conform to Mendelian inheritance laws. The MLPA results showed that the gene deletion was absent in the MEN1. The results from the third genetic detection (redesigned the primer) showed that they had a heterozygous mutation. The detection errors might due to an intron mutation. Conclusions: A new germline mutation, which can improve the identification of clinical phenotypes and the early diagnosis of MEN1, was identified. An intron mutation may lead to incorrect results of homozygous, which is incompatible with Mendelian genetic law. Redesigning the primers for gene detection could avoid this situation.

Multiple Endocrine Neoplasia Type 1: A Chinese Family with a new germline mutation(c.201delC) and Detection Errors due to an Intron Mutation

Background: Multiple endocrine neoplasia type 1 (MEN1) is a hereditary cancer syndrome caused by germline mutations in the MEN1 gene located on chromosome 11q13. The three main endocrine tissues affected most frequently by tumors in MEN1 are the parathyroid (95%), enteropancreatic neuroendocrine tissues (50%), and anterior pituitary (40%). The purpose of this study was to report on a Chinese family with a new heterozygous MEN1 mutation in exon 2 [NM_130802: c.201delC (p.Ala68Profs*51) with localization to Chr11:64577381 on assembly GRCh37].Methods: A 49-year-old female patient (proband) was admitted to the hospital due to intermittent recurrent hypoglycemia symptoms. After a series of examinations, we found that she had a pancreatic tumor, parathyroid tumor, adrenal tumor, and a suspicious gastrinoma. Due to the proband’s suspicious clinical manifestations of MEN1, we performed genetic detection for the proband and her immediate family members. We also used multiplex ligation-dependent probe amplification (MLPA) to rule out homozygous mutations caused by a deletion of gene fragments in the proband and her immediate family members.Results: A new MEN1 germline mutation [c.201delC (p.Ala68Profs*51)], which could induce MEN1, was found by the genetic test. Two of the proband’s six relatives were found by the genetic test to have the same mutations as the proband, and the proband’s sister also had the typical symptoms of MEN1. However, the first and second genetic detection results showed that they were homozygous mutations, which did not conform to Mendelian inheritance laws. The MLPA results showed that the gene deletion was absent in the MEN1. The results from the third genetic detection (redesigned the primer) showed that they were a heterozygous mutation. The detection errors were due to an intron mutation.Conclusions: A new germline mutation that induced MEN1, which can improve the identification of clinical phenotypes of MEN1 and the early diagnosis of the disease, was identified. An intron mutation may lead to incorrect results of homozygous, which is incompatible with Mendelian genetic law. Redesigning the primers for gene detection could avoid this situation.

Multiple Endocrine Neoplasia Type 1: A Chinese Family with a new germline mutation(c.201delC) and A Detection Errors due to Intron Mutation

Background: Multiple endocrine neoplasia type 1 (MEN1) is a hereditary cancer syndrome caused by germline mutations in the MEN1 gene located on chromosome 11q13. The three main endocrine tissues affected most frequently by tumors in MEN1 are the parathyroid (95%), enteropancreatic neuroendocrine tissues (50%), and anterior pituitary (40%). The purpose of this study was to report on a Chinese family with a new heterozygous MEN1 mutation in exon 2 [NM_130802: c.201delC (p.Ala68Profs*51) with localization to Chr11:64577381 on assembly GRCh37].Methods: A 49-year-old female patient (proband) was admitted to the hospital due to intermittent recurrent hypoglycemia symptoms. After a series of examinations, we found that she had a pancreatic tumor, parathyroid tumor, adrenal tumor, and suspicious gastrinoma. Due to the proband’s suspicious clinical manifestations of MEN1, we performed genetic detection for the proband and her immediate family members. To rule out homozygous mutations caused by deletion of gene fragments, the proband and her immediate family members were detected the MLPA (Multiplex ligation-dependent probe amplification).Results: A new MEN1 germline mutation [c.201delC (p.Ala68Profs*51)], which could induce MEN1, was found by the genetic test. Two of the proband’s six relatives were found by the genetic test to have the same mutations as the proband, and the proband’s sister has the typical symptoms of MEN1 as well. However, the first time and second time genetic detection results showed that they were homozygous mutation, it didn’t conform to Mendelian inheritance laws. The MLPA results showed that the gene deletion was absent in the MEN1. The third time genetic detection (redesigned the prime) showed that they were heterozygous mutation. This detection errors due to intron mutation.Conclusions: A new germline mutation that induced MEN1, which can improve the identification of clinical phenotypes of MEN1 and the early diagnosis of the disease, was identified. Intron mutation may lead to wrong results of homozygous, which incompatible with Mendelian genetic law. Redesign the primer for gene detection could avoid this situation.