中华医学遗传学杂志最新文献

Objective: To explore the genetic basis and pathogenesis for a child with type I Hereditary hemorrhagic telangiectasia (HHTⅠ) and Splenic sinus shore cell hemangioma (LCA).

Methods: A child with HHT complicated with LCA diagnosed at the First Affiliated Hospital of Dali University in April 2022 was selected as the study subject. Clinical data of the child and her relatives were collected, and pathogenic variants were screened by whole exome sequencing. Candidate variant was verified by Sanger sequencing and bioinformatic analysis.

Results: The patient, a 16-year-old female, had recurrent epitaxis since childhood, which sometimes necessitated hemostasis treatment. She also had splenectomy due to splenic rupture and was diagnosed with LCA. Her father and grandmother also had a history of recurrent epitaxis. Her father had deceased due to cerebral vascular rupture. The child was found to harbor a c.360+1G>A variant in the ENG gene. The same variant was not found in her asymptomatic mother and brother.

Conclusion: The c.360+1G>A variant of the ENG gene probably underlay the pathogenesis in this child.

Objective: To explore the clinical, imaging, and genetic characteristics of an adult patient with sporadic Neuronal intranuclear inclusion disease (NIID).

Methods: A patient who had visited the First People's Hospital of Chenzhou on August 6, 2023 was selected as the study subject. Results of clinical examination, neuroimaging, and genetic testing were retrospectively analyzed along with a literature review. The number of GGC trinucleotide repeats in the 5'-untranslated region of the NOTCH2NLC gene was determined by GC-PCR.

Results: The patient had presented with episodic encephalopathy, with enhanced magnetic resonance imaging showing enhancement features of the posterior cerebral cortex during the period of acute episode. Genetic testing revealed an increased number of GGC repeats (n = 97) in the 5'- untranslated region of the NOTCH2NLC gene, which confirmed the diagnosis of NIID.

Conclusion: Clinical attention should be paid to the enhanced MRI findings of patients with adult-onset NIID, for whom posterior cortical enhancement may be characteristic manifestation during the acute phase of encephalopathy-like episode.

Objective: To explore the clinical characteristics and variant of CREBBP gene in a fetus with Rubinstein-Taybi syndrome (RSTS).

Methods: A fetus with RSTS diagnosed at the Third Affiliated Hospital of Zhengzhou University in August 2022 was selected as the study subject. Clinical data, amniotic fluid sample of the fetus and peripheral blood samples of its parents were collected for whole exome sequencing (WES). Candidate variant was verified by Sanger sequencing.

Results: Foot malformation, cerebellar vermis agenesis, brain agenesis, polysyndactyly of the big toes and other phenotypes were found by prenatal ultrasound. WES revealed that the fetus has harbored a heterozygous c.4684G>T (p.E1562*) variant in exon 28 of the CREBBP gene (NM_004380.3), which was de novo in origin. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), the variant was predicted to be pathogenic (PVS1+PS2_Moderate+PM2_Supporting). After genetic counseling, the couple had opted to terminate the pregnancy and refused autopsy of the fetus.

Conclusion: The c.4684G>T (p.E1562*) variant of the CREBBP gene probably underlay the RSTS in this fetus. The newly discovered variant has enriched the mutational spectrum of the CREBBP gene and illustrated that WES is an efficient tool for the prenatal diagnosis of RSTS.

Objective: To explore the correlation between structural chromosomal abnormality and clinical characteristics of a child featuring gonadal dysplasia.

Methods: A 13-year-old child who was admitted to Lianyungang Maternal and Child Health Care Hospital on February 7, 2023 for primary amenorrhoea and occasional abdominal pain was selected as the study subject. Clinical data of the child was collected, and peripheral blood samples of the child and her parents were collected. G-banding chromosomal karyotyping and copy number variation sequencing (CNV-seq) were carried out. "Pseudodual centromere isochromosome X" and "psu idic(X)" were used as keywords to search the CNKI, Wanfang and PubMed databases, and the search period was set as from January 1, 2002 to June 1, 2023. Relevant literature on the structural abnormality of X chromosome was searched and analyzed retrospectively.

Results: The child has a height of 153 cm and weighed 45 kg. She has no obvious facial dysmorphism. Laboratory tests showed that she had higher FSH and luteinizing hormone, and lower E₂. Ultrasonography showed that she had small ovaries and rudimentary uterus. She was found to have a karyotype of 46,X,psu idic(X)(q21.3)[40]/mos 45,X[3], whilst both of her parents had a normal karyotype. CNV-seq showed that she had a 63.27 Mb deletion in Xq21.32q28 and a 91.59 Mb duplication in Xp22.33q21.32 (mosaicism rate = 74%). A total of 11 relevant literature were retrieved. Clinical phenotypes of patients with similar structural chromosomal abnormalities were diverse, which was closely related to the mosaicism rate of the 45,X karyotype and the location of the breaking point.

Conclusion: 46,X,psu idic(X)(q21.3)/45,X probably underlay the dysplasia of uterus and ovary and sex hormone abnormalities in this child, while her height was spared. Deletion of Xq21.32q28 is a key factor leading to Turner syndrome-like phenotype such as rudimentary uterus and ovarian dysplasia.

Objective: To explore the genetic basis and clinical phenotype of a Chinese pedigree affected with Focal segmental glomerulosclerosis (FSGS).

Methods: A male patient who was admitted to the First Affiliated Hospital of Zhengzhou University on July 26, 2018 was selected as the study subject. Clinical data of the patient was collected. Next generation sequencing and Sanger sequencing were carried out to detect the variant sites. Bioinformatic software was used to simulate the effect of candidate variant on the protein functions.

Results: Ultrasound exam of the patient showed enhanced echo for the renal parenchyma. Kidney biopsy had confirmed the pathological diagnosis of FSGS (non-specific). Electronic microscopy displayed segmental sclerosis of the glomeruli, mild hyperplasia of mesangial cells and matrix. The proband was found to harbor two novel variants of the PLCE1 gene, namely c.3199delA (p.N1067Mfs*15) and c.4441_4443delATC (p.1481_1481del), which were respectively inherited from his mother and father. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), both variants were rated as pathogenic (PVS1+PM2_Supporting+PP3; PM2_Supporting+PM3+PP3). Bioinformatic simulation suggested that both variants could significantly affect the tertiary structure of the PLCE1 protein.

Conclusion: The c.4441_4443delATC and c.3199delA variants of the PLCE1 gene probably underlay the pathogenesis of the FSGS in this pedigree.

Objective: To explore the clinical and genetic characteristics of three children with Leguis syndrome.

Methods: Three children suspected as Legius syndrome at the Henan Children's Hospital for precocious puberty or short stature from June 6, 2019 to August 25, 2022 were selected as the study subjects. Clinical data of the children were collected. All children were subjected to whole exome sequencing, and candidate variants were verified by Sanger sequencing.

Results: All of the children (including 2 females and 1 male, and aged 4 years and 6 months, 8 years, and 14 years and 8 months, respectively) had typical café de lait spots. Child 1 also had precocious puberty, and children 2 and 3 had short statures. Genetic testing revealed that all of them had harbored heterozygous variants of the SPRED1 gene, including c.751C>T (p.Arg251Ter194) in child 1, c.229A>T (p.Lys77Ter368) in child 2, and c.1044_1046delinsC (p.R349fs*11) in child 3. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), the c.751C>T (p.Arg251Ter194) variant was predicted to be likely pathogenic, whilst the other two were known pathogenic variants.

Conclusion: All of the three children were diagnosed with Leguis syndrome due to variants of the SPRED1 gene, which had manifested as multiple café de lait spots in conjunct with precocious puberty or short statures.

Objective: The clinical and molecular genetic characteristics of 46,XY disorders of sex development caused by NR5A1 gene variants in 15 cases were analyzed to improve the understanding of this disease.

Methods: The clinical data of children with NR5A1 gene variants diagnosed at the Children's Hospital Affiliated to Zhengzhou University from March 2016 to December 2021 were retrospectively analyzed. Whole exome sequencing was performed to confirm the candidate sites, and Sanger sequencing was performed for validation. The patients were treated and followed up according to their disease characteristics.

Results: At the initial diagnosis, 5 of the 15 cases were raised as females and 10 as males. The gonadal tissue was testis without residual Müllerian or ooticular structure, and all had various degrees of genital abnormalities. The average EMS masculinity score was 4.8 (1 ~ 9), including micropenis (100.0%), hypospadias (86.7%), unfused scrotum (46.7%), and abnormal testicular position (60.0%), in which the hypospadias was Ⅱ°~ Ⅳ°. There was no skin pigmentation in 5 patients with growth retardation. Chromosomal karyotypes were 46,XY, adrenocorticotropin and cortisol levels were normal, electrolyte levels were normal, HCG stimulation test in 5 cases had normal response, 9 cases had low response. Anti-Müllerian hormone and statin B had decreased abnormally with age. A total of 14 NR5A1 variants were detected in the 15 children, most of which occurred in exon 4, of which 9 variant loci were not included in the HGMD database as of December 2022.

Conclusion: The clinical phenotype of 46,XY abnormal sexual development caused by NR5A1 gene variants is extensive, with the external genitals showing varying degrees of insufficient masculinization. Adrenal involvement is rare.

DNA methylation is an important epigenetic regulatory mechanism which plays a crucial role in cell differentiation and development. Its function is closely related to DNA methyltransferase 3 alpha (DNMT3A), which can affect gene expression and stem cell differentiation. The mutation rate of the DNMT3A gene is relatively high in Acute myeloid leukemia (AML), but its type and pathogenic mechanism are not yet clear. Further research on DNMT3A may help to identify its pathogenic targets and provide a basis for precise treatment of AML. This article has provided a review for the research progress on the expression of the DNMT3A gene in AML.

Objective: To explore the clinical phenotype and genetic variant in a Chinese pedigree affected with Hunter syndrome and create immortalized cell lines for the affected pedigree members.

Methods: A pedigree of six members who had visited Xi'an Children's Hospital in July 2022 was selected as the study subject. Clinical data was collected. Whole exome sequencing was carried out for the pedigree members. Candidate variant was verified by Sanger sequencing. In addition, peripheral B lymphocytes were transfected with Epstein-Barr virus to create immortalized cell lines, which were then subjected to enzyme activity analysis.

Results: The patient, a five-year-and-seven-month-old boy, had exhibited stiff limbs and enlarged joints. He had developed hernia, scaphocephaly, and barrel chest from 3 months of age. His uncle also had stiff limbs, poor hearing, blindness, and right oblique inguinal hernia. Above features had resembled those of Hunter syndrome. Genetic testing revealed that both the child and his uncle had harbored an IDS (NM_000202.8): c.823G>A (p.D275N) variant, which was unreported previously. Bioinformatic analysis indicated that the D275 to be a highly conserved site, and the D275N variant may affect the stability of the protein's spatial conformation, thereby decrease the catalytic activity of the enzyme. The successfully constructed immortalized lymphoblastoid cell lines for the child and his parents showed increased volume, irregular shape, burr structure and cluster growth. And the value of IDS activity of the patient's immortalized lymphoblastoid cells was below the limit of detection. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), the variant was classified as likely pathogenic (PS3+PM2_Supporting+PM5+PP1+PP3).

Conclusion: Above finding has enriched the phenotypic and mutational spectra of Hunter syndrome, and provided a basis for the genetic counseling for this pedigree. The creation of immortalized cell lines has offered a model for further investigation of the impact of variant on the function of IDS and development of targeted drugs.

Objective: To carry out clinical and genetic analysis for a child featuring Brain-Lung-Thyroid syndrome (BLTS).

Methods: A child who had presented at the Children's Hospital Affiliated to Shandong University on May 27, 2022 was selected as the study subject. Clinical data was collected. Trio-whole exome sequencing (Trio-WES) was carried out for the child and his parents, and candidate variant was verified by Sanger sequencing and bioinformatic analysis. The child was given individualized treatment following the diagnosis.

Results: The child, a two-year-and-seven-month-old boy, had presented with global developmental delay, ataxia and hypothyroidism. WES revealed that he has harbored a heterozygous c.674C>T variant of the NKX2-1 gene, based on which he was diagnosed with BLTS. CT scan revealed interstitial and parenchymal inflammation in his lungs, which was reduced by budesonide aerosol inhalation.

Conclusion: Discovery of the novel c.674C>T variant has enriched the mutational spectrum of the NKX2-1 gene. Budesonide aerosol may be used to treat lung inflammation associated with BLTS.