G-quadruplex RNA Based PROTAC Enables Targeted Degradation of RNA Binding Protein FMRP for Tumor Immunotherapy.

Fragile X mental retardation protein (FMRP), an RNA binding protein (RBP), is aberrantly hyper-expressed in human tumors and plays an essential role in tumor invasion, metastasis and immune evasion. However, there is no small-molecule inhibitor for FMRP so far. In this study, we developed the first FMRP-targeting degrader based on PROteolysis TArgeting Chimera (PROTAC) technology and constructed a heterobifunctional PROTAC through linking a FMRP-targeting G-quadruplex RNA (sc1) to a von Hippel-Lindau (VHL)-targeting ligand peptide (named as sc1-VHLL). Sc1-VHLL specifically degraded endogenous FMRP via ubiquitination pathway in both mouse and human cancer cells. The FMRP degradation significantly changed the secretion pattern of cancer cells, resulting in higher expression of pro-inflammatory cytokine and smaller amounts of immunomodulatory contents. Furthermore, sc1-VHLL, when encapsulated into ionizable liposome nanoparticles (LNP) efficiently targeted tumor site and degraded FMRP in cancer cells. In CT26 tumor-bearing mouse model, FMRP degradation within tumors substantially promoted the infiltration of lymphocytes and CD8 T cells and reduced the proportion of Treg cells, reshaping the proinflammatory tumor microenvironment and accordingly transforming cold tumor into hot tumor. When combined with immune checkpoint blockade (ICB) therapy, sc1-VHLL based treatment remarkably inhibited the tumor growth.

Balancing the benefits and risks of China's national salt iodization policy over 30 years using disability-adjusted life years (DALYs): a systematic review and meta-analysis.

Both insufficient and excessive iodine intake can lead to thyroid-related disorders. Although China has made progress in eliminating iodine deficiency over the past few decades, the incidence of thyroid cancer is increasing. Currently, there is a lack of relevant research on the tradeoff between the benefits and risks of salt iodization in China. In this study, we developed a method that combines the total probability algorithm and disease burden to evaluate the appropriate amount of salt iodization. Following the principle of minimizing the comprehensive disease burden and using the metabolic model of human iodine nutrition. Based on the average national iodine level in water, the optimal iodine content in Chinese salt is determined to be 17 mg/kg. However, iodine content in water is not evenly distributed in China. Approximately 3.23% of administrative villages have water iodine concentrations exceeding 80 ug/L, eliminating the need for iodine fortification in salt. Approximately 83.51% of administrative villages need to continue implementing the salt iodization policy, with the optimal iodine content in salt ranging from 15 to 18 mg/kg. In 13.16% of administrative villages, the iodine content in salt is determined based on the local water iodine concentration, ranging from 0 to 15 mg/kg. Our study cracks open a window of insight suggesting that the optimal iodine content for salt is lower than the existing benchmark dictated by the prevailing policy in China. Hence, there is an urgent need to refine and advance the iodine supplementation strategy in salt to pave the way for precision medicine and health-centric iodine supplementation strategies.

Rare Case of de Novo 2p15 Microdeletion Syndrome with Deletion Covering XPO1 and USP34 Genes Diagnosed in a Child - A Case Report.

Introduction: 2p15p16.1 microdeletion syndrome was described for the first time in 2007. The size of the microdeletion is variable and encompasses several genes, like XPO1, USP34, BCL11A, REL, PAPOLG, PEX13, COMMD1, B3GNT2, and EHBP1. Features of the syndrome include short stature, microcephaly, hypotonia, psychomotor developmental delay, anomalies of the fingers of the upper and lower limbs, dysmorphic features like receding forehead, broad nasal bridge, telecanthus, ptosis, flat philtrum, small mouth with a high, narrow palate and everted lower lip. The precise genotype-phenotype correlation in 2p15 deletion syndrome is not understood. The aim of the study is to present the patient's medical history and the diagnostic process. Case Presentation: A boy aged 9 was admitted to the Genetic Outpatient Clinic due to dysmorphic features and mild mental retardation. Full lips, broad nasal root, very light hair, excessively developed subcutaneous tissue, joint laxity, postural defect, flat-valgus foot with sandal gap, brachydactyly, and problems with concentration, memory, and counting were found. Diagnosis was based on microarray testing, and copy-number variation analysis was performed using CytoScan 750K array. Genetic imbalance in the form of a deletion within the short arm of chromosome 2 in the 2p15 region (containing 50 kbp) was shown. The microdeletion covers 2 genes: USP34 and XPO1. Parents were not carriers of that mutation. Conclusion: The phenotypic features presented by the patient were reflected in the genetic test. 2p15 microdeletion syndrome is genetically heterogeneous with possible de novo occurrence, as in the presented case. The precise genotype-phenotype correlation in 2p15 deletion syndrome should be widely studied because in the literature there is mainly mentioned 2p15p16.1 syndrome. Even though 2p15 microdeletion syndrome is a rare discovery and its features are mainly mild, it is necessary to pay special attention to them to refer patients to genetic counseling to make an accurate diagnosis.

A 12-year Life History of a Girl with Profound Intellectual Disability and Leukoencephalopathy: A Rare Clinical Presentation of X Chromosome Pentasomy.

This paper presents a unique 12-year case analysis of a girl with Penta-X syndrome, a chromosomal abnormality characterized by five X chromosomes instead of the normal two in healthy women. Pentasomy of X is a genetic, but not a hereditary disease affecting only women. Our patient demonstrated delayed mental, speech, and motor development along with physical anomalies such as craniofacial deformities, and eye pathology and was diagnosed with pentasomy of the X chromosome at the age of 3 after a cytogenetic examination. She developed epileptic seizures at the age of nine. Magnetic resonance imaging(MRI) revealed leukoencephalopathy with ventriculomegaly. The peculiarity of this observation is that the polysomy 49, XXXXX detected in the patient is characterized by a typical phenotypic presentation combined with demyelinating leukoencephalopathy, which has not been a typical feature of the disorder.

High-grade serous carcinoma of the fallopian tube in a young woman with chromosomal 4q abnormality: A case report.

BACKGROUND: Few studies have reported an association between an increased risk of acquiring cancers and survival in patients with 4q deletion syndrome. This study presents a rare association between chromosome 4q abnormalities and fallopian tube high-grade serous carcinoma (HGSC) in a young woman. CASE SUMMARY: A 35-year-old woman presented with acute dull abdominal pain and a known chromosomal abnormality involving 4q13.3 duplication and 4q23q24 deletion. Upon arrival at the emergency room, her abdomen appeared ovoid and distended with palpable shifting dullness. Ascites were identified through abdominal ultrasound, and computed tomography revealed an omentum cake and an enlarged bilateral adnexa. Blood tests showed elevated CA-125 levels. Paracentesis was conducted, and immunohistochemistry indicated that the cancer cells favored an ovarian origin, making us suspect ovarian cancer. The patient underwent debulking surgery, which led to a diagnosis of stage IIIC HGSC of the fallopian tube. Subsequently, the patient received adjuvant chemotherapy with carboplatin and paclitaxel, resulting in stable current condition. CONCLUSION: This study demonstrates a rare correlation between a chromosome 4q abnormality and HGSC. UBE2D3 may affect crucial cancer-related pathways, including P53, BRCA, cyclin D, and tyrosine kinase receptors, thereby possibly contributing to cancer development. In addition, ADH1 and DDIT4 may be potential influencers of both carcinogenic and therapeutic responses.

Corrigendum: Dysregulation of BMP, Wnt, and insulin signaling in fragile X syndrome.

[This corrects the article DOI: 10.3389/fcell.2022.934662.].

[High expression of fragile X mental retardation protein inhibits ferroptosis of colorectal tumor cells by activating the RAS/MAPK signaling pathway].

OBJECTIVE: To investigate the mechanism by which fragile X mental retardation protein (FMRP) regulates ferroptosis evasion in colorectal cancer (CRC) cells. METHODS: We examined FMRP expression levels in CRC cell lines using RT-qPCR and Western blotting and analyzed the biological functions and signaling pathways involved in FMRP-mediated regulation of CRC progression using the TCGA database. A lentiviral FMRP overexpression vector (Lv-FMRP) and 3 knockdown vectors (siFMRP-1, siFMRP-2, and siFMRP-3) were constructed, and their effects on proliferation of HCT116 cells were examined using CCK8 assay and plate clone formation assay; the changes in cell ferroptosis level was determined using MDA/ROS/GSH/Fe2+ kits, mitochondrial membrane potential changes were detected using JC-1 fluorescence staining, and the expressions of proteins associated with ferroptosis and the RAS/MAPK signaling pathway were detected using Western blotting. The subcutaneous tumorigenic potential of the transfected cells was evaluated in nude mice. RESULTS: Compared with normal colonic mucosal epithelial NCM460 cells, the CRC cell lines had significantly higher FMRP expression level. Bioinformatics analysis suggested the involvement of FMRP in regulation of reactive oxygen, oxidative stress-induced cell death, mitochondrial respiration, and glutathione metabolism pathways. In the cell experiments, FMRP knockdown significantly inhibited proliferation of HCT116 cells, lowered cellular GSH content, increased MDA and ROS levels, Fe2+ fluorescence intensity, and mitochondrial membrane potential, and decreased SLC7A11/GPX4 protein expressions and the phosphorylation levels of ERK, MEK, MAPK, and RAS proteins; FMRP overexpression resulted in the opposite changes in the cells. In the tumor-bearing nude mice, HCT116 cells with FMRP knockdown showed attenuated tumorigenic potential with lowered xenograft growth rate and reduced SLC7A11 expression in the xenograft. CONCLUSION: The high expression of FMRP inhibits ferroptosis in CRC cells and promotes progression of CRC by activating the RAS/MAPK signaling pathway.

Diagnosis, treatment, and management of esophageal foreign bodies in patients with mental retardation: A retrospective study from three centers.

Background: This study aims to assess the outcomes and prognosis of surgical interventions aimed at removing esophageal foreign bodies in patients with mental retardation. Methods: Between January 2010 and January 2021, a total of 30 consecutive patients (20 males, 10 females; median age: 29.5 years; range, 2 to 57 years) with mental retardation who were diagnosed with esophageal foreign bodies and underwent surgical treatment were retrospectively analyzed. Age and sex of the patients, symptoms, type of the foreign body, esophageal stricture level, methods used for preoperative diagnosis, type of surgical procedure, postoperative complications, and length of hospital stay were recorded. Results: Seventeen (56.6%) patients had a foreign body in the first narrowing, 12 (40%) in the second narrowing, and one (3.3%) in the third narrowing. A rigid esophagoscopy was performed in all cases. However, successful removal was not achieved in two (6.6%) cases, and foreign bodies were removed through cervical esophagotomy in one (3.3%) patient and through esophagotomy with right thoracotomy in one (3.3%) patient. Postoperative complications included esophagitis in seven patients (23.3%) and wound infection and pneumonia in two patients (6.6%). The median length of hospital stay after treatment was 1.09 days in patients without complications and 3.3 days in patients with complications. There was a significant correlation between the occurrence of complications and the length of hospital stay (p=0.002). The foreign body was successfully removed in all patients, and no mortality was observed. Conclusion: Early diagnosis and emergency intervention can reduce complications, particularly considering the possibility of non-food and sharp-edged foreign bodies that pose a higher risk of damaging the digestive system, in patients with mental retardation than those without such conditions.

A Novel Mutation Diagnosing in Allan-Herndon-Dudley's Syndrome.

Allan-Herndon-Dudley's syndrome (AHDS) is a rare X-linked recessive disease that causes abnormal serum thyroid function tests, severe hypotonia, intellectual disability, and motor deficit due to a mutation in the monocarboxylate transporter 8, which is a thyroid hormone transporter. A 6-month-old male patient presented to our outpatient clinic with a serious hypotonia complaint. With a preliminary diagnosis of AHDS, a molecular genetic examination was performed. The molecular genetic analysis detected a new previously unidentified variant in the SLC16A2 gene. This case has been presented to report the AHDS, which is a rare cause of hypotonia in patients presenting/consulting with severe hypotonia, global developmental delay, and abnormal thyroid function test results. Besides, a novel pathogenic mutation in the SLC16A2 gene has been described in the present article.

Involvement and regulation of the left anterior cingulate cortex in the ultrasonic communication deficits of autistic mice.

Introduction: Autism spectrum disorder (ASD) is a group of diseases often characterized by poor sociability and challenges in social communication. The anterior cingulate cortex (ACC) is a core brain region for social function. Whether it contributes to the defects of social communication in ASD and whether it could be physiologically modulated to improve social communication have been poorly investigated. This study is aimed at addressing these questions. Methods: Fragile X mental retardation 1 (FMR1) mutant and valproic acid (VPA)-induced ASD mice were used. Male-female social interaction was adopted to elicit ultrasonic vocalization (USV). Immunohistochemistry was used to evaluate USV-activated neurons. Optogenetic and precise target transcranial magnetic stimulation (TMS) were utilized to modulate anterior cingulate cortex (ACC) neuronal activity. Results: In wild-type (WT) mice, USV elicited rapid expression of c-Fos in the excitatory neurons of the left but not the right ACC. Optogenetic inhibition of the left ACC neurons in WT mice effectively suppressed social-induced USV. In FMR1-/-- and VPA-induced ASD mice, significantly fewer c-Fos/CaMKII-positive neurons were observed in the left ACC following USV compared to the control. Optogenetic activation of the left ACC neurons in FMR1-/- or VPA-pretreated mice significantly increased social activity elicited by USV. Furthermore, precisely stimulating neuronal activity in the left ACC, but not the right ACC, by repeated TMS effectively rescued the USV emission in these ASD mice. Discussion: The excitatory neurons in the left ACC are responsive to socially elicited USV. Their silence mediates the deficiency of social communication in FMR1-/- and VPA-induced ASD mice. Precisely modulating the left ACC neuronal activity by repeated TMS can promote the social communication in FMR1-/- and VPA-pretreated mice.

Late-onset cerebellar ataxia and a new frameshift L2HGDH mutation in a Chinese adult with L-2-hydroxyglutaric aciduria: a case report.

L-2-Hydroxyglutaric aciduria (L2HGA) is a rare, autosomal recessive neurometabolic disease, which presents with elevated L-2-hydroxyglutarate acid. Generally, L2HGA appear as slowly progressing central nervous system function deterioration during infancy, and a rapid progression in adulthood is uncommon for the syndrome's classic phenotype.

Mosaicism-independent mechanisms contribute to Pcdh19-related epilepsy and repetitive behaviors in Xenopus.

Protocadherin19 (PCDH19)-related epilepsy syndrome is a rare disorder characterized by early-onset epilepsy, intellectual disability, and autistic behaviors. PCDH19 is located on the X chromosome and encodes a calcium-dependent single-pass transmembrane protein, which regulates cell-to-cell adhesion through homophilic binding. In human, 90% of heterozygous females, containing PCDH19 wild-type and mutant cells due to random X inactivation, are affected, whereas mutant males, containing only mutant cells, are typically not. The current view, the cellular interference, is that the altered interactions between wild-type and mutant cells during development, rather than loss of function itself, are responsible. However, studies using Pcdh19 knockout mice showed that the complete loss of function also causes autism-like behaviors both in males and females, suggesting that other functions of PCDH19 may also contribute to pathogenesis. To address whether mosaicism is required for PCDH19-related epilepsy, we generated Xenopus tropicalis tadpoles with complete or mosaic loss of function by injecting antisense morpholino oligonucleotides into the blastomeres of neural lineage at different stages of development. We found that either mosaic or complete knockdown results in seizure-like behaviors, which could be rescued by antiseizure medication, and repetitive behaviors. Our results suggest that the loss of PCDH19 function itself, in addition to cellular interference, may also contribute to PCDH19-related epilepsy.

The First Korean Case with Cardiac, Facial, and Digital Anomalies with Developmental Delay Caused by De Novo TRAF7 p.Arg655Gln Variant.

TRAF7-related disorders represent some of the rarest inherited disorders, exhibiting clinical features that overlap with cardiac, facial, and digital anomalies with developmental delay (CAFDADD) syndrome, as well as blepharophimosis-mental retardation syndrome (BMRS). A 36-year-old male, presenting with total blindness, blepharophimosis, and intellectual disability, was admitted for the assessment of resting dyspnea several months previously. He had a history of being diagnosed with obstructive sleep apnea (OSA). Transesophageal and transthoracic echocardiography unveiled right ventricular dilatation without significant pulmonary hypertension, bicuspid aortic valve with aortic root aneurysm, and aortic regurgitation in the proband. Sanger sequencing identified a de novo TRAF7 variant (c.1964G>A; p.Arg655Gln). Subsequently, aortic root replacement using the Bentall procedure was performed. However, despite the surgery, he continued to experience dyspnea. Upon re-evaluating OSA with polysomnography, it was discovered that continuous positive airway pressure support alleviated his symptoms. The underlying cause of his symptoms was attributed to OSA, likely exacerbated by the vertebral anomaly and short neck associated with CAFDADD syndrome. Clinicians should be attentive to the symptoms associated with OSA as it is a potentially serious medical condition in patients with TRAF7 variants.

RNA analysis and computer-aided facial phenotyping help to classify a novel TRIO splice site variant.

Pathogenic variants in TRIO, encoding the guanine nucleotide exchange factor, are associated with two distinct neurodevelopmental delay phenotypes: gain-of-function missense mutations within the spectrin repeats are causative for a severe developmental delay with macrocephaly (MIM: 618825), whereas loss-of-function missense variants in the GEF1 domain and truncating variants throughout the gene lead to a milder developmental delay and microcephaly (MIM: 617061). In three affected family members with mild intellectual disability/NDD and microcephaly, we detected a novel heterozygous TRIO variant at the last coding base of exon 31 (NM_007118.4:c.4716G>A). RNA analysis from patient-derived lymphoblastoid cells confirmed aberrant splicing resulting in the skipping of exon 31 (r.4615_4716del), leading to an in-frame deletion in the first Pleckstrin homology subdomain of the GEF1 domain: p.(Thr1539_Lys1572del). To test for a distinct gestalt, facial characteristics of the family members and 41 previously published TRIO cases were systematically evaluated via GestaltMatcher. Computational analysis of the facial gestalt suggests a distinguishable facial TRIO-phenotype not outlined in the existing literature.

Role of PIGM and PIGX in glycosylphosphatidylinositol biosynthesis and human health (Review).

Glycosylphosphatidylinositol-glycan (GPI) is an anchor to specific cell surface proteins known as GPI-anchored proteins (APs) that are localized in lipid rafts and may act as cell co-receptors, enzymes and adhesion molecules. The present review investigated the significance of GPI biosynthesis class phosphatidylinositol-glycan (PIG)M and PIGX in GPI synthesis and their implications in human health conditions. PIGM encodes GPI-mannosyltransferase I (MT-I) enzyme that adds the first mannose to the GPI core structure. PIGX encodes the regulatory subunit of GPI-MT-I. The present review summarizes characteristics of the coding sequences of PIGM and PIGX, and their expression in humans, as well as the relevance of GPI-MT-I and the regulatory subunit in maintaining the presence of GPI-APs on the cell surface and their secretion. In addition, the association of PIGM mutations with paroxysmal nocturnal hemoglobinuria and certain types of GPI-deficiency disease and the altered expression of PIGM and PIGX in cancer were also reviewed. In addition, their interaction with other proteins was described, suggesting a complex role in cell biology. PIGM and PIGX are critical genes for GPI synthesis. Understanding gene and protein regulation may provide valuable insights into the role of GPI-APs in cellular processes.

Genetic analysis of a pedigree with MECP2 duplication syndrome in China.

BACKGROUND: MECP2 duplication syndrome (MDS) is a rare X-linked genomic disorder that primarily affects males. It is characterized by delayed or absent speech development, severe motor and cognitive impairment, and recurrent respiratory infections. MDS is caused by the duplication of a chromosomal region located on chromosome Xq28, which contains the methyl CpG binding protein-2 (MECP2) gene. MECP2 functions as a transcriptional repressor or activator, regulating genes associated with nervous system development. The objective of this study is to provide a clinical description of MDS, including imaging changes observed from the fetal period to the neonatal period. METHODS: Conventional G-banding was employed to analyze the chromosome karyotypes of all pedigrees under investigation. Subsequently, whole exome sequencing (WES), advanced biological information analysis, and pedigree validation were conducted, which were further confirmed by copy number variation sequencing (CNV-seq). RESULTS: Chromosome karyotype analysis revealed that a male patient had a chromosome karyotype of 46,Y,dup(X)(q27.2q28). Whole-exon duplication in the MECP2 gene was revealed through WES results. CNV-seq validation confirmed the presence of Xq27.1q28 duplicates spanning 14.45 Mb, which was inherited from a mild phenotype mother. Neither the father nor the mother's younger brother carried this duplication. CONCLUSION: In this study, we examined a male child in a family who exhibited developmental delay and recurrent respiratory tract infections as the main symptoms. We conducted thorough family investigations and genetic testing to determine the underlying causes of the disease. Our findings will aid in early diagnosis, genetic counseling for male patients in this family, as well as providing prenatal diagnosis and reproductive guidance for female carriers.

Algorithmic approach utilizing histology and immunohistochemistry for the current classification of diffuse glioma.

INTRODUCTION: Diffuse glioma constitutes 28% of primary brain tumors. Until recently morphologic appearance was the only criterion for classifying these tumors. However, WHO 2016 incorporates molecular information in the primary diagnosis of gliomas such as Isocitrate dehydrogenase 1 (IDH1), Alpha thalassemia/mental retardation syndrome X inked (ATRX) as well as 1p/19q codeletion on FISH. In a resource-limited setup where FISH is not available, Alpha internexin (INA) has been suggested as a surrogate IHC marker. MATERIAL AND METHODS: Cross-sectional study conducted in the Department of Pathology for two years. Tissue blocks and clinical as well as radiological details were obtained from departmental archives. After assessing the morphologic details, routine IHC markers such as GFAP, Ki67 and P53 along with molecular markers like IDH-1, ATRX, and lNA were applied. RESULTS: Out of 55 cases of diffuse glioma, 23 cases of astrocytoma and 32 cases of oligodendroglioma with an overall mean age of presentation of 41.49 ± 12.47 years. IDH-1 expression among diffuse glioma was 89.1% in our study. Alteration in the ATRX gene expression was observed in 95.7% of astrocytomas. 75% of oligodendrogliomas expressed INA with no significant difference in expression between the two grades. Based on the algorithmic approach using molecular surrogate markers, diffuse gliomas were categorized into six distinct groups. IDH-mutant, ATRX loss of expression astrocytoma and IDH-mutant, INA positive oligodendroglioma are two categories that do not require further molecular testing. This comprises 72.7% of the cases and these do not warrant further workup. CONCLUSION: Implementation of combined phenotypic-genotypic diagnosis with the use of histomorphology and immunohistochemical surrogates for molecular genetic alterations will yield more homogeneous and narrowly defined diagnostic entities which will provide better prognostication and definitive treatment. It also is cost-effective in a resource-limited setup.

Intrauterine ultrasound phenotyping, molecular characteristics, and postnatal follow-up of fetuses with the 15q11.2 BP1-BP2 microdeletion syndrome: a single-center, retrospective clinical study.

OBJECTIVES: The 15q11.2 BP1-BP2 microdeletion is associated with neurodevelopmental diseases. However, most studies on this microdeletion have focused on adults and children. Thus, in this study, we summarized the molecular characteristics of fetuses with the 15q11.2 BP1-BP2 microdeletion and their postnatal follow-up to guide prenatal diagnosis. METHODS: Ten thousand fetuses were retrospectively subjected to karyotype analysis and chromosome microarray analysis. RESULTS: Chromosome microarray analysis revealed that 37 (0.4%) of the 10,000 fetuses had 15q11.2 BP1-BP2 microdeletions. The fragment size of the 15q11.2 BP1-BP2 region was approximately 312-855 kb and encompassed TUBGCP5, CYFIP1, NIPA2, and NIPA1 genes. Twenty-five of the 37 fetuses with this microdeletion showed phenotypic abnormalities. The most common ultrasonic structural abnormality was congenital heart disease, followed by renal dysplasia and Dandy-Walker malformation. The 15q11.2 BP1-BP2 microdeletion was inherited from the father and mother in 6 and 10 cases, respectively, and de novo inherited in 4 cases. In the postnatal follow-up, 16.1% of the children had postnatal abnormalities. CONCLUSION: Fetuses with the 15q11.2 BP1-BP2 microdeletion showed high proportions of phenotypic abnormalities, but the specificity of penetrance was low. Thus, fetuses with this syndrome are potentially at a higher risk of postnatal growth/behavioral problems and require continuous monitoring of growth and development.

Investigating the effects of a single ASPM variant (c.8508_8509) on brain architecture among siblings in a consanguineous Pakistani family.

BACKGROUND: Autosomal Recessive Primary Microcephaly (MCPH) is a rare, neurodevelopmental disorder associated with mild to severe mental retardation. It is characterized by reduced cerebral cortex that ultimately leads to reduction in skull size less than - 3 S.D below the mean for normal individuals having same age and sex. Till date, 30 known loci have been reported for MCPH. METHODS: In the present study, Sanger sequencing was performed followed by linkage analysis to validate the mutation in ASPM gene of the consanguineous Pakistani clans. Bioinformatics tools were also used to confirm the pathogenicity of the diseased variant in the gene. MRI scan was used to compare the brain structure of both the affected individuals (Aslam et al. in Kinnaird's 2nd International Conference on Science, Technology and Innovation, Lahore, 2023). RESULTS: Our study described a consanguineous family with two patients with a known ASPM (MCPH5) variant c.8508_8509delGA causing a frameshift mutation in exon 18 which located in calmodulin-binding IQ domain of the ASPM protein. The salient feature of this study is that a single variant led to significantly distinct changes in the architecture of brain of both siblings which is further confirmed by MRI results. The computation analysis showed that the change in the conservation of this residue cause this variant highly pathogenic. Carrier screening and genetic counselling were also remarkable features of this study (Aslam et al. in Kinnaird's 2nd International Conference on Science, Technology and Innovation, Lahore, 2023). CONCLUSION: This study explores the extraordinary influence of a single ASPM variant on divergent brain structure in consanguineous siblings and enable us to reduce the incidence of further microcephalic cases in this Pakistani family (Aslam et al. in Kinnaird's 2nd International Conference on Science, Technology and Innovation, Lahore, 2023).