The connection between the gut microbiota and brain structure changes is still unclear. We conducted a Mendelian randomization (MR) study to examine the bidirectional causality between the gut microbiota (211 taxa, including 131 genera, 35 families, 20 orders, 16 classes and 9 phyla; N = 18,340 individuals) and age-independent/dependent longitudinal changes in brain structure across the lifespan (N = 15,640 individuals aged 4~99 years). We identified causal associations between the gut microbiota and age-independent/dependent longitudinal changes in brain structure, such as family Peptostreptococcaceae with age-independent longitudinal changes of cortical gray matter (GM) volume and genus Faecalibacterium with age-independent average cortical thickness and cortical GM volume. Taking age-independent longitudinal changes in brain structure across the lifespan as exposures, there were causal relationships between the surface area and genus Lachnospiraceae. Our findings may serve as fundamentals for further research on the genetic mechanisms and biological treatment of complex traits and diseases associated with the gut microbiota and the brain structure change rate.

Nonsyndromic orofacial clefts (NSOFCs) are the most common human craniofacial defects. Genetic factors play a critical role in the pathogenesis of NSOFCs. However, known causal genes only explain a minority of the estimated heritability. To unveil the underlying genetic architecture, exome sequencing is performed on 214 sporadic patients with NSOFCs. The findings substantiate the genetic and allelic heterogeneity of NSOFCs and underscore the crucial role of dysregulation of OFC‐related signaling pathways in the occurrence of NSOFCs. Besides, the candidate variants discovered provide a fruitful resource for further genetic studies. Particularly, three BOC missense variants (p.R407W, p.G436S, and p.D1018N) are identified in three unrelated cases with cleft palate. In parallel, a BOC nonsense variant (p.R681X), co‐segregating with a GLI2 missense variant (p.A543G), is identified in a multiplex family with microform cleft lip. Functional studies demonstrate while the four BOC variants are hypomorphic alleles, the GLI2 variant is a hypermorphic allele. The counteraction between BOC p.R681X allele and GLI2 p.A543G allele accounts for the mild phenotype in the multiplex family. Thus, this study establishes BOC as a novel causal gene and implicates a two‐locus model of inheritance via the epistatic antagonism of two SHH pathway variants in NSOFCs.

The Hedgehog (HH) signaling plays key roles in embryogenesis and organogenesis, and its dysfunction causes a variety of human birth defects. Orofacial cleft (OFC) is one of the most common congenital craniofacial defects, and its etiology is closely related to mutations in multiple components in the HH pathway, including the PTCH1 receptor. A quantity of PTCH1 variants have been associated with OFC, but the pathogenicity and underlying mechanism of these variants have not been functionally validated. In our previous studies, we identified two PTCH1 variants (A392V and R945X) in two families with hereditary OFC. Here we explore the functional consequences of these two variants. In zebrafish embryos, microinjection of wild type PTCH1 mRNA causes curved body axis and craniofacial anomalies. In contrast, microinjection of A392V and R945X PTCH1 mRNAs results in much milder phenotypes, suggesting these two variants are loss-of-function mutations. In mammalian cells, A392V and R945X mutations reverse the inhibitory effect of PTCH1 on HH signaling. Biochemically, the two mutants PTCH1 show lower expression levels and shortened half-life, indicting these mutations decrease the stability of PTCH1. A392V and R945X mutations also appear to cause PTCH1 to localize away from vesicles. Taken together, our findings indicate that A392V and R945X variants are loss-of-function mutations that disrupt the function of PTCH1 and thus cause dysregulation of HH signaling, leading to the pathogenesis of OFC.

Orofacial clefts (OFCs) represent the most prevalent congenital craniofacial anomalies, significantly impacting patients' appearance, oral function, and psychological well-being. Among these, non-syndromic OFCs (NSOFCs) are the most predominant type, with the etiology attributed to a combination of genetic and environmental factors. Rare variants of key genes involved in craniofacial development-related signaling pathway are crucial in the occurrence of NSOFCs, and our recent studies have identified PTCH1, a receptor-coding gene in the Hedgehog signaling pathway, as a causative gene for NSOFCs. However, the role of PTCH2, the paralog of PTCH1, in pathogenesis of NSOFCs remains unclear. Here, we perform whole-exome sequencing to explore the genetic basis of 144 sporadic NSOFC patients. We identify five heterozygous variants of PTCH2 in four patients: p.L104P, p.A131G, p.R557H, p.I927S, and p.V978D, with the latter two co-occurring in a single patient. These variants, all proven to be rare through multiple genomic databases, with p.I927S and p.V978D being novel variants and previously unreported. Sequence alignment suggests that these affected amino acids are evolutionarily conserved across vertebrates. Utilizing predictive structural modeling tools such as AlphaFold and SWISS-MODEL, we propose that these variants may disrupt the protein's structure and function. In summary, our findings suggest that PTCH2 may be a novel candidate gene predicted to be associated with NSOFCs, thereby broadening the spectrum of causative genes implicated in the craniofacial anomalies.

The human epidermal growth factor receptor 2 (HER2) is a major therapeutic target in cancer. While the oncogenic effects of HER2 hyperactivation are well characterized, the biological consequences of its deficiency remain poorly defined. Here, through exome sequencing analyses of a cohort of 720 families affected by isolated or syndromic orofacial clefts, we unexpectedly identified 5 distinct rare germline HER2 variants in 5 unrelated families with growth deficits, orofacial clefts, and other craniofacial, skeletal, and auditory anomalies. In Xenopus embryos, these variants failed to recapitulate the developmental effects of WT HER2. In cultured cells, they disrupted HER2 protein stability, membrane localization, or site-specific phosphorylation, resulting in diminished ERK signaling. Strikingly, knock-in mice expressing a patient-derived HER2 variant and mice maternally exposed to Tucatinib, a recently approved anti-HER2 drug, both replicated patient phenotypes: delayed growth and diverse craniofacial abnormalities, including ocular dysgenesis, short jaws, and cleft palate. Collectively, our findings define a developmental disorder that we designate GRACE syndrome (Growth Retardation and Craniofacial Malformations Caused by HER2 Deficiency), establish HER2’s essential role in human growth and craniofacial morphogenesis, and reveal that HER2-targeted therapies during pregnancy can induce craniofacial defects and lifelong growth impairment in fetuses.

Purpose: This study aimed to investigate the associations between maternal smoking (MS) and education score in adult offspring. Methods: To better understand this link, we performed a two-stage genome-wide by environment interaction studies (GWEIS) of MS and offspring education score in UK Biobank cohort. Specifically, 276 996 subjects from England were enrolled in the discovery study, while 24 355 subjects from Scotland and 14 526 subjects from Wales were enrolled in the replication study. GWEIS were conducted by PLINK 2.0 with MS used as an environmental risk factor. Results: Significant GWEIS associations (P < 0.0001) between MS and offspring education score in both the discovery cohort and two replicate cohorts (Scotland population and Wales population) were identified. GWEIS identified 2 independent significant single nucleotide polymorphism–MS interaction, with one variant located in the chromosomal 16 (rs72768988, Position: 22,768,798, P = 1.22 × 10^-8, β = 6.7662) and the other one located in 2q32.3 region (2 : 196424612_GT_G, Position: 196 424 612, 3.60 × 10^-9, β = −0.4721). Conclusion: Our results suggested 2q32.3 region and HECW2 gene could negatively moderate the influence of MS on offspring's educational status.