Dibyendu Dutta

T‐complex protein 1 ( TCP1 ) encodes the TCP1α subunit, one of eight subunits of the chaperonin containing TCP1 ring complex (TRiC). Heterozygous TCP1 variants cause autosomal dominant neurodevelopmental disorder characterized by developmental delay or intellectual disability, seizures, pyramidal or cerebellar signs, and brain malformations, particularly polymicrogyria. However, the reported clinical spectrum remains limited. We report a 4‐year‐old girl with global developmental delay, speech and motor delay, behavioral dysregulation, microcephaly, hypotonia with core weakness, and a previously unreported heterozygous likely pathogenic TCP1 variant, c.1392delT (p.A465Qfs*3). This frameshift variant is located in exon 11, truncates the final 16.5% of the protein, is predicted to undergo nonsense‐mediated decay, and is absent from gnomAD. Biological parental testing was unavailable, precluding determination of variant inheritance. Brain magnetic resonance imaging (MRI) demonstrated an absent septum pellucidum with mild bilateral frontal sulcation/gyration asymmetry without polymicrogyria; the optic nerves and pituitary were normal. No seizures were documented through age 4 years. Additional findings included bicuspid aortic valve with mild aortic insufficiency, asthma, severe eczema/atopy, and multiple food allergies. This case suggests that the molecular and neuroimaging spectrum of TCP1 ‐related neurodevelopmental disorder may be broader than previously recognized; however, a causal association between TCP1 and absent septum pellucidum cannot be established from a single case. The relationship of the cardiac and atopic findings to TCP1 remains uncertain. Additional cases and functional studies are needed to clarify genotype–phenotype relationships.

Börjeson–Forssman–Lehmann syndrome (BFLS) is a rare X-linked neurodevelopmental disorder caused by pathogenic variants in the plant homeodomain finger protein 6 ( PHF6 ) gene. Core features include developmental delay, intellectual disability, dysmorphic craniofacial characteristics, obesity, hypogonadism and digital anomalies. Orofacial clefting has not been recognised as part of the canonical phenotype and is rarely reported in association with BFLS. One cohort study listed cleft lip and/or palate as an uncommon feature without individual case details, and a separate report described a female with a nonsense PHF6 variant and clefting of the hard and soft palate. Here, we describe a BFLS female with a de novo missense PHF6 variant who presented with cleft palate. This case adds to the emerging evidence that clefting, though uncommon, may be a recurrent manifestation. It supports the inclusion of PHF6 in the genetic testing of patients presenting with syndromic orofacial clefting when accompanied by neurodevelopmental delay or dysmorphism.

Background: Duplications involving Xp22.33, particularly within the pseudoautosomal region 1 (PAR1), are rare. While copy number variants (CNVs) involving SHOX, a dosage-sensitive gene in PAR1, are known to cause growth disorders, large duplications encompassing the entire PAR1 region and beyond show variable associations with skeletal and neurodevelopmental abnormalities. Duplication of the near-complete, isolated PAR1 with a comprehensive clinical description has not been reported. Case Presentation: We report a male patient with a 2.49 Mb duplication encompassing nearly the entire PAR1 region (chrX:200854–2692897, GRCh37). Clinical features included global developmental delay (GDD), autism spectrum disorder (ASD), recurrent seizures, hypotonia with joint hypermobility, dysmorphic features, and proportionate tall stature. The duplicated segment contains 30 genes, including 15 protein-coding genes that escape X-inactivation. Among these, SHOX, DHRSX, ASMT, and CSF2RA are notable candidates contributing to the observed phenotype. Conclusions: This report presents a detailed clinical characterization of a rare, near-complete, isolated PAR1 duplication in a male individual. The co-occurrence of tall stature, GDD, ASD, and seizures raises the possibility of a dosage-related phenotypic effect involving one or more genes within the duplicated interval. While causality cannot be definitively established, these observations contribute to the emerging understanding of the functional consequences of Xp22.33 duplications and suggest that increased copy number within this region may be associated with a clinically significant neurodevelopmental phenotype.

Background: Chromosome 19 is the most gene-dense chromosome in the human genome, with a high frequency of segmental duplications that predispose it to genomic rearrangements. While deletions of chromosome 19 have been associated with various clinical conditions, duplications remain poorly characterised. Here, we report three cases involving 19p13.11 duplication and describe the associated clinical phenotype. Methods: We describe three unrelated individuals with microduplications at 19p13.11 identified either via clinical whole-exome sequencing or chromosomal microarray. The probands underwent detailed clinical genetic evaluations, and CNVs were confirmed with parental testing when available. Sequencing reads were aligned to the GRCh37/hg19 human genome build. Results: All three probands exhibited neurodevelopmental delays, attention-deficit/hyperactivity disorder and speech delay. Additional overlapping features included joint hypermobility, short stature and craniofacial anomalies. Patient-specific manifestations included haematological abnormalities, musculoskeletal asymmetries and cardiac findings. Duplicated regions spanned 1.2–1.6 Mb and encompassed 41–49 protein-coding genes. Patients 2 and 3 have CNVs that overlap 76% with those of Patient 1. Several genes have predicted high triplosensitivity scores and are associated with autosomal dominant neurodevelopmental and skeletal disorders. Patient 1, with the largest duplication, had more extensive systemic involvement, likely reflecting the broader gene dosage effect. Conclusion: This is the first comprehensive clinical and molecular characterisation of 19p13.11 duplications, suggesting a recurring multisystem phenotype driven by gene dosage sensitivity. These findings support the inclusion of 19p13.11 duplications in diagnostic evaluations for neurodevelopmental and multisystem disorders.

The zinc finger homeobox 3 ( ZFHX3 ) gene encodes a transcription factor involved in neurodevelopment and organogenesis. ZFHX3 haploinsufficiency is linked to intellectual disability, epilepsy and neurodevelopmental defects, but its potential involvement in neural tube defects (NTDs) and related structural anomalies is unknown. We report a female proband with a de novo heterozygous ZFHX3 variant (NM_006885.3: c.5876 A>C, p.(Gln1959Pro), identified via exome sequencing. She presented with spina bifida occulta, segmental spinal dysgenesis, bilateral clubfeet, bicuspid aortic valve and genital anomaly. This report suggests an expanded phenotypic spectrum of ZFHX3 -associated disorders. Given the known interactions of ZFHX3 with Wnt/β-catenin, mTOR and Hippo signalling pathways, we hypothesise that disruptions in these networks could contribute to NTDs and skeletal defects. No functional studies were performed, so causality cannot be established. Further research and reports of similar phenotypes in ZFHX3 variants are needed to confirm its role in NTDs and other congenital structural anomalies.

Nizon-Isidor syndrome (NIZIDS) is a rare neurodevelopmental disorder caused by heterozygous MED12L variants, where previously pathogenic single-nucleotide variants (SNVs) were only reported as de novo events. Here, we report the first case of maternally inherited MED12L nonsense variant in NIZIDS. Clinical assessment and family history evaluation revealed global developmental delay, intellectual disability, autism spectrum disorder, and speech impairment. Exome sequencing (ES) of the proband and both parents confirmed the presence of a maternally inherited likely pathogenic MED12L nonsense variant in the proband. Additional pathogenic variants in GAMT (maternal) and TNFRSF13B (paternal) genes were also identified in the proband. The clinical history of the mother suggested variable expressivity of the MED12L variant. Our case report challenges the presumed de novo inheritance of MED12L SNVs and demonstrates variable expressivity, thereby highlighting the benefit of a complete phenotype-driven approach when analyzing exome and genome data.

Background: Previous reports of distal deletions in chromosome 10q in patients have described distinct facial features combined with other neurodevelopmental abnormalities, including intellectual disability. However, the association of interstitial deletions in chromosome 10q with global developmental delay, musculoskeletal abnormalities, and dysmorphic features has not been previously reported. Methods: Genetic testing using whole exome sequencing (WES) was performed on three patients with neurodevelopmental delay, musculoskeletal abnormalities and dysmorphic features. Sequencing reads were aligned to the human genome build GRCh37/UCSC hg19 and analysed for both sequence and copy number variants. Results: WES identified similar interstitial deletions in the 10q21.1q21.3 locus in all three patients. The deleted region includes online Mendelian inheritance in man (OMIM)-annotated genes with clinical significance, such as ANK3 (*600465), JMJD1C (*604503), EGR2 (*129010), BICC1 (*614295), ZNF365 (*607818) and TFAM (*600438). Deletion of this region is considered pathogenic and is implicated in the aetiology of the clinical phenotypes observed in these patients. Conclusions: This is the first report associating interstitial deletions in the 10q21.1q21.3 locus with neurodevelopmental delay, musculoskeletal abnormalities and dysmorphic features. Our findings highlight the clinical significance of this deleted region and suggest possible mechanisms underlying the observed pathological phenotypes.

Background and Objectives: In sickle cell disease (SCD), hepatopathy is a cumulative consequence of ischemia/reperfusion (I/R) injury from a vaso-occlusive crisis, tissue inflammation, and iron overload due to blood transfusion. Hepatopathy is a major contributing factor of shortened life span in SCD patients. We hypothesized that the voxelotor, a hemoglobin allosteric modifier, ameliorates sickle hepatopathy. Materials and Methods: Townes SCD mice and their controls were treated with either chow containing GBT1118, a voxelotor analog, or normal chow. We evaluated inflammation, fibrosis, apoptosis and ferroptosis in their livers using qPCR, ELISA, histology, and immunohistochemistry. Results: GBT1118 treatment resulted in reduced hemolysis, iron overload and inflammation in the liver of SCD mice. There were significant reductions in the liver enzyme levels and bile acids. Furthermore, GBT1118-treated mice exhibited reduced apoptosis, necrosis, and fibrosis. Increased ferroptosis as evident from elevated 4-hydroxynonenal (4-HNE) staining, malondialdehyde (MDA) levels, and expression of Ptgs2 and Slc7a11 mRNAs, were also significantly reduced after GBT1118 treatment. To explain the increased ferroptosis, we evaluated iron homeostasis markers in livers. SCD mice showed decreased expression of heme oxygenase-1, ferritin, hepcidin, and ferroportin mRNA levels. GBT1118 treatment significantly increased expressions of these genes. Conclusions: Our results suggest GBT1118 treatment in SCD confers the amelioration of sickle hepatopathy by reducing inflammation, fibrosis, apoptosis, iron overload and ferroptosis.