Genetic Analysis Research Articles

Genetic analysis and assisted reproductive guidance for two infertile patients with rare small supernumerary marker chromosomes

To carry out cytogenetic and molecular genetic analysis for two infertile patients carrying rare small supernumerary marker chromosomes (sSMC). Two infertile patients who received reproductive and genetic counseling at CITIC Xiangya Reproductive and Genetic Hospital on October 31, 2018 and May 10, 2021, respectively were selected as the study subjects. The origin of sSMCs was determined by conventional G banding, fluorescence in situ hybridization (FISH) and copy number variation sequencing (CNV-seq). Microdissection combined with high-throughput whole genome sequencing (MicroSeq) was carried out to determine the fragment size and genomic information of their sSMCs. For patient 1, G-banded karyotyping and FISH revealed that he has a karyotype of mos47,XY,del(16)(p10p12),+mar[65]/46,XY,del(16)(p10p12)[6]/48,XY,del(16)(p10p12),+2mar[3].ish mar(Tel 16p-,Tel 16q-,CEP 16-,WCP 16+). CNV analysis has yielded a result of arr[GRCh37]16p12.1p11.2(24999364_33597595)×1[0.25]. MicroSeq revealed that his sSMC has contained the region of chromosome 16 between 24979733 and 34023115 (GRCh37). For patient 2, karyotyping and reverse FISH revealed that she has a karyotype of mos 47,XX,+mar[37]/46,XX[23].rev ish CEN5, and CNV analysis has yielded a result of seq[GRCh37]dup(5)(p12q11.2)chr5:g(45120001_56000000)dup[0.8]. MicroSeq results revealed that her sSMC has contained the region of chromosome 5 between 45132364 and 55967870(GRCh37). After genetic counseling, both couples had opted in vitro fertilization (IVF) treatment and preimplantation genetic testing (PGT). For individuals harboring sSMCs, it is vital to delineate the origin and structural characteristics of the sSMCs for their genetic counseling and reproductive guidance. Preimplantation genetic testing after microdissection combined with high-throughput whole genome sequencing (MicroSeq-PGT) can provide an alternative treatment for carrier couples with a high genetic risk.

Genetic analysis and trait association in F2 populations of four different crosses in pigeonpea (Cajanus cajan L. Millsp.)

Genetic analysis and trait association in F2 populations of four different crosses in pigeonpea (Cajanus cajan L. Millsp.)

Like Father, Like Daughter - Ectodermal Dysplasia-Syndactyly Syndrome: A Case Report.

Ectodermal dysplasia-syndactyly syndrome 1 (EDSS1) is an exceedingly rare condition associated with mutations in the PVL4 gene. It is characterised by sparse, brittle hair, eyebrows and eyelashes, abnormal dentition and nails, along with bilateral cutaneous syndactyly involving the fingers and toes. We report a 2-year-old girl who presented to us with bilateral complete simple syndactyly of the third and fourth web spaces of the hands, along with bilateral syndactyly of both feet involving the second to fourth toes. Upon examination, sparse hair and eyebrows, along with abnormal dentition, were noted. Thorough clinical examination and genetic analysis were conducted on the affected child and her father, who exhibited similar clinical features. Genetic analysis revealed a homozygous nonsense mutation in the PVL4 gene in both individuals. According to the literature, EDSS1 has been reported in only 10 families worldwide, and there are no reported cases from India. Level of Evidence: Level V (Therapeutic).

Inflammation and cancer: friend or foe?

Chronic inflammation plays a crucial role in the onset and progression of pathologies like neurodegenerative and cardiovascular diseases, diabetes, and cancer, since tumor development and chronic inflammation are linked, sharing common signaling pathways. At least 20% of breast and colorectal cancers are associated with chronic inflammation triggered by infections, irritants, or autoimmune diseases. Obesity, chronic inflammation, and cancer interconnection underscore the importance of population-based interventions in maintaining healthy body weight, to disrupt this axis. Given that the dietary inflammatory index is correlated with an increased risk of cancer, adopting an anti-inflammatory diet supplemented with nutraceuticals may be useful for cancer prevention. Natural products and their derivatives offer promising antitumor activity with favorable adverse effect profiles; however, the development of natural bioactive drugs is challenging due to their variability and complexity, requiring rigorous research processes. It has been shown that combining anti-inflammatory products, such as non-steroidal anti-inflammatory drugs (NSAIDs), corticosteroids, and statins, with plant-derived products demonstrate clinical utility as accessible adjuvants to traditional therapeutic approaches, with known safety profiles. Pharmacological approaches targeting multiple proteins involved in inflammation and cancer pathogenesis emerge as a particularly promising option. Given the systemic and multifactorial nature of inflammation, comprehensive strategies are essential for long term success in cancer therapy. To gain insights into carcinogenic phenomena and discover diagnostic or clinically relevant biomarkers, is pivotal to understand genetic variability, environmental exposure, dietary habits, and TME composition, to establish therapeutic approaches based on molecular and genetic analysis. Furthermore, the use of endocannabinoid, cannabinoid, and prostamide-type compounds as potential therapeutic targets or biomarkers requires further investigation. This review aims to elucidate the role of specific etiological agents and mediators contributing to persistent inflammatory reactions in tumor development. It explores potential therapeutic strategies for cancer treatment, emphasizing the urgent need for cost-effective approaches to address cancer-associated inflammation.

An interpretable model of pre-mRNA splicing for animal and plant genes.

Pre-mRNA splicing is a fundamental step in gene expression, conserved across eukaryotes, in which the spliceosome recognizes motifs at the 3' and 5' splice sites (SSs), excises introns, and ligates exons. SS recognition and pairing is often influenced by protein splicing factors (SFs) that bind to splicing regulatory elements (SREs). Here, we describe SMsplice, a fully interpretable model of pre-mRNA splicing that combines models of core SS motifs, SREs, and exonic and intronic length preferences. We learn models that predict SS locations with 83 to 86% accuracy in fish, insects, and plants and about 70% in mammals. Learned SRE motifs include both known SF binding motifs and unfamiliar motifs, and both motif classes are supported by genetic analyses. Our comparisons across species highlight similarities between non-mammals, increased reliance on intronic SREs in plant splicing, and a greater reliance on SREs in mammalian splicing.

Whole-genome resequencing deciphers patterns of genetic diversity, phylogeny, and evolutionary dynamics in Kashmir cattle.

Kashmir cattle, which were kept by local pastoralists for centuries, are exceptionally resilient and adaptive to harsh environments. Despite its significance, the genomic characteristics of this cattle breed remain elusive. This study utilized whole genome sequences of Kashmir cattle (n = 20; newly sequenced) alongside published whole genomes of 32 distinct breeds and seven core cattle populations (n = 135). The analysis identified ~25.87 million biallelic single nucleotide polymorphisms in Kashmir cattle, predominantly in intergenic and intron regions. Population structure analyses revealed distinct clustering patterns of Kashmir cattle with proximity to the South Asian, African and Chinese indicine cattle populations. Genetic diversity analysis of Kashmir cattle demonstrated lower inbreeding and greater nucleotide diversity than analyzed global breeds. Homozygosity runs indicated less consanguineous mating in Kashmir cattle compared with European taurine breeds. Furthermore, six selection sweep detection methods were used within Kashmir cattle and other cattle populations to identify genes associated with vital traits, including immunity (BOLA-DQA5, BOLA-DQB, TNFAIP8L, FCRL4, AOAH, HIF1AN, FBXL3, MPEG1, CDC40, etc.), reproduction (GOLGA4, BRWD1, OSBP2, LEO1 ADCY5, etc.), growth (ADPRHL1, NRG2, TCF12, TMOD4, GBP4, IGF2, RSPO3, SCD, etc.), milk composition (MRPS30 and CSF1) and high-altitude adaptation (EDNRA, ITPR2, AGBL4 and SCG3). These findings provide essential genetic insights into the characteristics and establish the foundation for the scientific conservation and utilization of Kashmir cattle breed.

Risk and Resilience Variants in the Retinoic Acid Metabolic and Developmental Pathways Associated with Risk of FASD Outcomes

Fetal Alcohol Spectrum Disorder (FASD) is a common neurodevelopmental disorder that affects an estimated 2–5% of North Americans. FASD is induced by prenatal alcohol exposure (PAE) during pregnancy and while there is a clear genetic contribution, few genetic factors are currently identified or understood. In this study, using a candidate gene approach, we performed a genetic variant analysis of retinoic acid (RA) metabolic and developmental signaling pathway genes on whole exome sequencing data of 23 FASD-diagnosed individuals. We found risk and resilience alleles in ADH and ALDH genes known to normally be involved in alcohol detoxification at the expense of RA production, causing RA deficiency, following PAE. Risk and resilience variants were also identified in RA-regulated developmental pathway genes, especially in SHH and WNT pathways. Notably, we also identified significant variants in the causative genes of rare neurodevelopmental disorders sharing comorbidities with FASD, including STRA6 (Matthew–Wood), SOX9 (Campomelic Dysplasia), FDG1 (Aarskog), and 22q11.2 deletion syndrome (TBX1). Although this is a small exploratory study, the findings support PAE-induced RA deficiency as a major etiology underlying FASD and suggest risk and resilience variants may be suitable biomarkers to determine the risk of FASD outcomes following PAE.

Genetic analysis of a fetus with cryptophthalmos due to variants of FREM2 gene

To explore the genetic etiology of a fetus with cryptophthalmos detected by prenatal ultrasonography. A fetus undergoing induced labor at 32nd gestational week due to absence of bilateral eye fissures detected by prenatal ultrasonography in January 2017 was selected as the study subject. Umbilical cord blood sample from the fetus and peripheral blood samples from its parents were collected for the extraction of genomic DNA. Pathogenic variants were screened through whole exome sequencing (WES) and verified by Sanger sequencing. Pathogenicity of candidate variants was verified by bioinformatic analysis and protein structure simulation. Based on the results of genetic testing, prenatal diagnosis was provided to the couple upon their subsequent pregnancy. The couple had four adverse pregnancies previously. The aborted fetus was the fifth, with fused bilateral upper and lower eyelids, poorly developed eyeballs, adhesion of the cornea with the upper eyelid, low-set ears, and abnormal plantar creases, and was diagnosed with cryptophthalmos. WES and Sanger sequencing revealed that the fetus has harbored compound heterozygous variants of the FREM2 gene, namely c.4537G>A (p.D1513N) and c.7292C>T (p.T2431M). Both variants were unreported associated with cryptophthalmos previously. Protein structure simulation showed that they may lead to loss of hydrogen bonds in the protein product. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), both variants were predicted to be likely pathogenic (PM1_Supporting+PM2_Supporting+PM5+PP3+PP4; PM2_Supporting+PM3+PP3+PP4). The mother was performed prenatal diagnosis in her sixth pregnancy based on the variants detected in this family, and delivered a daughter with normal phenotype. The FREM2: c.4537G>A and c.7292C>T compound heterozygous variants probably underlay the pathogenesis of cryptophthalmos in this fetus. Above finding has enriched the mutational spectrum of the FREM2 gene.

Clinical and genetic analysis of a patient with Baraitser-Winter syndrome due to variant of ACTG1 gene

To explore the clinical features and genetic etiology of a child with Baraitser-Winter syndrome (BWS). A BWS child who had sought medical attention at the Linyi People's Hospital on April 8, 2022 was selected as the study subject. Clinical data of the child was collected, and peripheral blood samples were obtained from the child and his parents. Whole exome sequencing (WES) was carried out, and candidate variant was verified by Sanger sequencing and bioinformatic analysis. The child, a 5-year-and-6-month-old male, had typical clinical features of BWS including congenital non-myogenic ptosis, arched eyebrows, wide philtrum, and pointed chin. Neurological symptoms included microcephaly, developmental delay, epilepsy, and deafness. Cranial MRI revealed enlarged frontal lobes, decreased white matter, and hydrocephalus. WES has identified a heterozygous c.430G>A (p.Asn144Tyr) missense variant in the ACTG1 gene. Sanger sequencing confirmed that neither of his parents has carried the same variant. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), the variant was classified as likely pathogenic (PS2+PM2_Supporting+PP3_Moderate+PP4). The heterozygous c.430G>A (p.Asn144Tyr) missense variant of the ACTG1 gene probably underlay the pathogenesis of BWS in this child. Above finding has enriched the mutation spectrum of BWS-related genes and provided a basis for clinical diagnosis and genetic counseling.

The OsMOB1A–OsSTK38 kinase complex phosphorylates CYCLIN C, controlling grain size and weight in rice

Abstract Grain size and weight are crucial yield-related traits in rice (Oryza sativa). Although certain key genes associated with rice grain size and weight have been successfully cloned, the molecular mechanisms underlying grain size and weight regulation remain elusive. Here, we identified a molecular pathway regulating grain size and weight in rice involving the MPS ONE BINDER KINASE ACTIVATOR-LIKE 1A–SERINE/THREONINE-PROTEIN KINASE 38–CYCLIN C (OsMOB1A–OsSTK38–OsCycC) module. OsSTK38 is a nuclear Dbf2-related kinase that positively regulates grain size and weight by coordinating cell proliferation and expansion in the spikelet hull. OsMOB1A interacts with and enhances the autophosphorylation of OsSTK38. Specifically, the critical role of the OsSTK38 S322 site in its kinase activity is highlighted. Furthermore, OsCycC, a component of the Mediator complex, was identified as a substrate of OsSTK38, with enhancement by OsMOB1A. Notably, OsSTK38 phosphorylates the T33 site of OsCycC. The phosphorylation of OsCycC by OsSTK38 influenced its interaction with the transcription factor KNOTTED-LIKE HOMEOBOX OF ARABIDOPSIS THALIANA 7 (OsKNAT7). Genetic analysis confirmed that OsMOB1A, OsSTK38 and OsCycC function in a common pathway to regulate grain size and weight. Taken together, our findings revealed a connection between the Hippo signalling pathway and the Cyclin-Dependent Kinase (CDK) module in eukaryotes. Moreover, they provide insights into the molecular mechanisms linked to yield-related traits and propose innovative breeding strategies for high-yielding varieties.

Phenotypic and genetic analysis of a Chinese pedigree affected with type 1 Otopalatodigital syndrome

To analyze the clinical phenotype and genetic basis of a Chinese pedigree affected with Otopalatodigital syndrome type 1 (OPD1). A pedigree which was evaluated at the Department of Endocrinology, General Hospital of the Central Theater Command on December 3, 2020 was selected as the study subject. Clinical phenotype and genetic features of the proband were analyzed. Whole exome sequencing was employed to screen for genetic variants in the proband, and Sanger sequencing was used to verify the candidate variants in the proband's mother, uncle, maternal aunt, and paternal aunt. Pathogenicity analysis was also conducted for the candidate variants. The proband, a 16-year-old male, had shown distinctive facial features including mildly prominent eyebrows, down-slanting palpebral fissures, hypertelorism, and depressed nasal bridge. Additionally, he had clubbing of bilateral thumbs and big toes, and central type diabetes insipidus. Genetic sequencing revealed that he has harbored a heterozygous c.586C>T (p.R196W) missense variant of the FLNA gene (NM_001110556.2), which was also carried by his mother and uncle. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), this variant was classified as likely pathogenic (PM1+PM2_Supporting+PP2+PP3+PS4 Supporting). The heterozygous c.586C>T (p.R196W) variant of the FLNA gene probably underlay the pathogenesis in this OPD1 family. The central type diabetes insipidus in the proband may represent a newly discovered phenotype of OPD1. Above finding has contributed crucial information for the comprehensive understanding of the clinical manifestations and pathogenic mechanisms of OPD1.

CgSSR marker based trait associations for Sitotroga cerealella (Olivier) resistance in stored paddy rice

Rice is stored for a longer time and many primary and secondary insect pests attack grains, causing both quantitative and qualitative losses. Physicochemical characteristics of grain influence stored grain insect susceptibility and resistance. Identification of gene/Quantitative Trait Loci (QTLs) and introgression in the cultivars would provide the desired solution for varietal resistance against S. cerealella. A group of 80 rice varieties was used for genetic analysis for the identification of candidate genes responsible for Sitotroga cerealella resistance. Heat maps derived from values in the kinship matrix were used to group the varieties into three subpopulations. The largest subpopulation has 34 varieties, while the lowest had 19. The first three principal components (PCs) explained 16, 9, and 6 percent of total variation, respectively, as indicated by the Principal Component Analysis (PCA). The PCA results complemented the heat map results in defining population structure. Genome-wide association mapping can detect marker-trait associations/QTLs in a heterogeneous population of breeding lines, despite population structure and unequal family relatedness. As shown by the Genomic Association and Prediction Integrated Tool (GAPIT) heat map, there are three subpopulations in the association mapping panel. Two cgSSR markers, related to gene SDG725 and FLO2, were linked to the attributes and responsible for conferring resistance against S. cerealella infestation. This is the first report of association and that would help in the development of cultivar with S. cerealella resistance.

Clinical features and genetic analysis of 17 Chinese pedigrees affected with X-linked intellectual disability

To analyze the clinical features and genetic etiology of 17 Chinese pedigrees affected with X-linked intellectual disability (XLID). Seventeen pedigrees affected with unexplained intellectual disability which had presented at Henan Provincial People's Hospital from May 2021 to May 2023 were selected as the study subjects. Clinical data of the probands and their pedigree members were collected. Trio-whole exome sequencing (Trio-WES), Sanger sequencing and X chromosome inactivation (XCI) analysis were carried out. Pathogenicity of candidate variants was predicted based on the guidelines from the American College of Medical Genetics and Genomics and co-segregation analysis. The 17 probands, including 9 males and 8 females with an age ranging from 0.6 to 8 years old, had all shown mental retardation and developmental delay. Fourteen variants were detected by genetic testing, which included 4 pathogenic variants (MECP2: c.502C>T, MECP2: c.916C>T/c.806delG, IQSEC2: c.1417G>T), 4 likely pathogenic variants (MECP2: c.1157_1197del/c.925C>T, KDM5C: c.2128A>T, SLC6A8: c.1631C>T) and 6 variants of uncertain significance (KLHL15: c.26G>C, PAK3: c.970A>G/c.1520G>A, GRIA3: c.2153C>G, TAF1: c.2233T>G, HUWE1: c.10301T>A). The PAK3: c.970A>G, GRIA3: c.2153C>G and TAF1: c.2233T>G variants were considered as the genetic etiology for pedigrees 12, 14 and 15 by co-segregation analysis, respectively. The proband of pedigree 13 was found to have non-random XCI (81:19). Therefore, the PAK3: c.1520G>A variant may underlie its pathogenesis. Trio-WES has attained genetic diagnosis for the 17 XLID pedigrees. Sanger sequencing and XCI assay can provide auxiliary tests for the diagnosis of XLID.

Herpes simplex encephalitis due to a mutation in an E3 ubiquitin ligase

Encephalitis is a rare and potentially fatal manifestation of herpes simplex type 1 infection. Following genome-wide genetic analyses, we identified a previously uncharacterized and very rare heterozygous variant in the E3 ubiquitin ligase WWP2, in a 14-month-old girl with herpes simplex encephalitis. The p.R841H variant (NM_007014.4:c.2522G > A) impaired TLR3 mediated signaling in inducible pluripotent stem cells-derived neural precursor cells and neurons; cells bearing this mutation were also more susceptible to HSV-1 infection compared to control cells. The p.R841H variant increased TRIF ubiquitination in vitro. Antiviral immunity was rescued following the correction of p.R841H by CRISPR-Cas9 technology. Moreover, the introduction of p.R841H in wild type cells reduced such immunity, suggesting that this mutation is linked to the observed phenotypes.

Clinical and genetic analysis of a Chinese patient with Alström syndrome

To explore the genetic etiology for a patient with Alström syndrome (ALMS) presenting as dilated cardiomyopathy. A 41-year-old male patient who had presented at the Sixth Medical Center of PLA General Hospital on October 20, 2021 was selected as the study subject. Clinical and laboratory examinations were carried out. Whole exome sequencing (WES) was employed for genetic testing, and candidate variants were validated by Sanger sequencing and pathogenicity analysis. The patient had a 14-year medical history characterized by dilated cardiomyopathy, complete atrioventricular block, visual impairment, sensorineural hearing loss, truncal obesity, insulin resistance, type 2 diabetes, hypertension, renal dysfunction, and paranoid delusions. Genetic testing revealed that he has harbored compound heterozygous variants of the ALMS1 gene, namely c.6823C>T (p.Arg2275Ter) and c.9442_9445dup (p.Ser3149LysfsTer2). Sanger sequencing confirmed that they were inherited from his father and mother, respectively. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), both variants were predicted to be pathogenic (PVS1_VeryStrong+PM2_Supporting+PM3+PP3, PVS1_VeryStrong+PM2_Supporting+PM3). Literature review indicated that the complete atrioventricular block in the patient was a phenotype unreported previously. The c.6823C>T (p.Arg2275Ter) and c.9442_9445dup (p.Ser3149LysfsTer2) compound heterozygous variants of the ALMS1 gene probably underlay the pathogenesis in this patient. Above findings have expanded the phenotypic spectrum of ALMS and provided insights for clinicians dealing with similar cases.

PE (Prickly Eggplant) encoding a cytokinin-activating enzyme responsible for the formation of prickles in eggplant

Abstract Eggplant is one of the most important vegetables worldwide, with some varieties displaying prickles. These prickles, present on the leaves, stems, and fruit calyxes, pose challenges during cultivation, harvesting, and transportation, making them an undesirable agronomic trait. However, the genetic mechanisms underlying prickle morphogenesis in eggplant remain poorly understood, impeding genetic improvements. In this study, genetic analyses revealed that prickle morphogenesis is governed by a single dominant nuclear gene, termed PE (Prickly Eggplant). Subsequent bulk segregant RNA-sequencing (BSR-seq) and linkage analysis preliminarily mapped PE to chromosome 6. This locus was then fine mapped to a 9,233-bp interval in a segregating population of 1109 plants, harboring only one candidate gene, SmLOG1, which encodes a LONELY GUY (LOG)-family cytokinin biosynthetic enzyme. Expression analyses via transcriptome and qRT-PCR demonstrate that SmLOG1 is predominantly expressed in immature prickles. CRISPR-Cas9 knockout experiments targeting SmLOG1 in prickly parental line 'PI381159' abolished prickles across all tissues, confirming its critical role in prickle morphogenesis. Sequence analysis of SmLOG1 pinpointed variations solely within the non-coding region. We developed a CAPS marker from a distinct SNP located at -735-bp within the SmLOG1 promoter, finding significant association with prickle variation in 190 eggplant germplasms. These findings enhance our understanding of the molecular mechanisms governing prickle development in eggplant and facilitate the use of marker-assisted selection (MAS) for breeding prickleless cultivars.

Clinical and molecular genetic analysis of a child with comorbid 16p11.2 microdeletion syndrome and Rett syndrome

To explore the genetic characteristics of a child with comorbid 16p11.2 microdeletion syndrome and Rett syndrome (RTT). A male infant who was admitted to Gansu Provincial Maternity and Child Health Care Hospital in May 2020 was selected as the study subject. Clinical data of the infant was collected. Genomic DNA was extracted from peripheral blood samples from the infant and his parents, and subjected to whole exome sequencing (WES). Candidate variant was verified by Sanger sequencing. The patient, a 4-day-old male infant, had presented with poor response, poor intake, feeding difficulties, and deceased at 8 months after birth. WES revealed that he has harbored a 0.643 Mb deletion in the 16p11.2 region, which encompassed key genes of the 16p11.2 microdeletion syndrome such as ALDOA, CORO1A, KIFF22, PRRT2 and TBX6. His father has carried the same deletion, but was phenotypically normal. The deletion was predicted to be pathogenic. The child was also found to harbor a maternally derived c.763C>T (p.R255X) hemizygous variant of the MECP2 gene, which was also predicted to be pathogenic (PVS1+PS4+PM2_Supporting). The 16p11.2 deletion and the MECP2: c.763C>T (p.R255X) variant probably underlay the pathogenesis in this infant.

Genetic analysis of a Chinese pedigree affected with Brachydactyly type B1 due to a novel variant of ROR2 gene

To explore the genetic basis for a Chinese pedigree affected with Brachydactyly type B1 (BDB1) through whole exome sequencing (WES). A BDB1 pedigree admitted to the Affiliated Women and Children's Hospital of Qingdao University on June 25, 2021 was selected as the study subject. Clinical data of the pedigree was collected with informed consent. WES was carried out for the proband, and candidate variant was verified by Sanger sequencing and bioinformatic analysis. WES and Sanger sequencing had identified a heterozygous c.2257delT variant in the ROR2 gene of the proband and his affected father, which has conformed to an autosomal dominant pattern of inheritance. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), the variant was classified to be likely pathogenic (PVS1_Strong+PM2 Supporting+PP4). The c.2257delT variant of the ROR2 gene was unreported previously and is strongly correlated with the BDB1-like phenotype in this pedigree. Above finding has enriched the mutational spectrum of the ROR2 gene and facilitated the diagnosis and genetic counseling for this pedigree.

Prenatal phenotype and genetic analysis of a fetus with Fibrochondrogenesis 1 due to compound heterozygous variants of COL11A1 gene

To explore the genetic etiology of a fetus with short limbs identified by prenatal ultrasonography. A fetus detected with short limb malformations at Shengjing Hospital Affiliated to China Medical University on October 25, 2021 was selected as the study subject. Prenatal ultrasound and post-abortion imaging were carried out to determine the phenotypic characteristics of the fetus. Amniotic fluid sample of the fetus and peripheral blood samples of its parents were collected. Following extraction of genomic DNA, whole-exome sequencing was carried out. Candidate variants were verified by Sanger sequencing. Online software was used to predict the structural changes of the mutant proteins. Prenatal ultrasound showed that the fetus had a small bell-shaped thorax, markedly shortened limbs, flat midface, a small nose with anteriorly tilted nostrils, and a small mandible. Post-abortion CT showed typical short and wide fetal ribs, cupped metaphyses at both ends, short long bones with wide metaphyses, resulting in a dumbbell-shaped appearance and curved thoracic vertebrae. Whole-exome sequencing revealed that the fetus had harbored compound heterozygous variants of the COL11A1 gene, namely c.2251G>T and c.3790G>T, both of which were predicted to alter the important Gly-X-Y structure of collagen protein. Sanger sequencing confirmed that the variants were respectively inherited from its parents. A rare fetus with Fibrochondrogenesis type 1 due to compound heterozygous variants of the COL11A1 gene has been diagnosed. Above finding has enabled genetic counseling and reproductive guidance for this family.

Clinical and genetic analyses of APMR4 syndrome caused by novel biallelic LSS variants

Alopecia intellectual disability syndromes 4 (APMR4) caused by Lanosterol synthase (LSS) gene variants is a very rare autosomal recessive neuroectodermal syndrome. It is characterized by congenital alopecia and variable degrees of intellectual disability (ID), frequently associated with developmental delay (DD) and epilepsy. Currently, only three studies regarding LSS-related APMR4 have been reported, the pathogenesis of APMR4 is poorly understood. We studied one patient with LSS-related APMR4 who presented with severe intellectual disability, alopecia, early-onset epilepsy and developmental delay. She is absence of hair on the eyebrows, eyelashes, and scalp. Two novel LSS variants (c.401 T > G and c.369C > G) were detected with whole-exome sequencing (WES). Analysis via WB experiment indicated that c.369 > G reduced the protein expression level of LSS. Analysis of protein stability prediction showed a destabilizing for LSS caused by the variant c.401 T > G. This study is the first study in Asia to date. These findings expanded the variantal spectrum of LSS-related APMR4 and revealed the potential pathogenic mechanism of LSS gene variants.