Human Genetics and Genomics Advances

PurposeFacial dysmorphism is a feature of many monogenic disorders, and is important in diagnostics, variant interpretation and nosology. Nevertheless, comprehensively assessing the complex facial shape changes associated with specific syndromes remains challenging. Here, we present 3D morphometric approaches to overcome these limitations, utilizing Cri-du-Chat syndrome (CdCS) as a model. MethodsWe analyzed 3D facial photos from 24 individuals with CdCS, 4540 unaffected controls and 5 individua...

This study investigates the genetic underpinnings of congenital tooth agenesis (CTA) using a multi-omics approach, integrating whole exome sequencing (WES)and RNA expression analysis. WES was used to analyze the genetic basis of CTA in six affected individuals one with syndromic and five with non-syndromic CTA alongside three healthy and two internal controls. We identified both known and novel variants in candidate genes (EDA, WNT10A, PAX9, TSPEAR) and assessed the functional impacts of novel v...

Nonsyndromic orofacial clefts (OFCs) are common, heritable birth defects caused by both genetic and environmental risk factors. Despite the identification of many genetic loci harboring OFC-risk variants, there are many unknown genetic determinants of OFC. Furthermore, while the process of embryonic facial development is well characterized, the molecular mechanisms that underly it are not. This represents a major hurdle in understanding how disruptions in these biological processes result in OFC...

BackgroundOculoauriculovertebral Spectrum (OAVS) encompasses abnormalities on derivatives from the first and second pharyngeal arches including macrostomia, hemifacial microsomia, micrognathia, preauricular tags, ocular and vertebral anomalies. We present genetic findings on a three-generation family affected with macrostomia, preauricular tags and uni- or bilateral ptosis following an autosomal dominant pattern. MethodsWe generated whole genome sequencing data for the proband, affected parent ...

BackgroundHereditary hemorrhagic telangiectasia (HHT) is considered a fully penetrant autosomal dominant disorder characterized by the development of arteriovenous malformations. Up to 96% of HHT cases are caused by heterozygous loss-of-function mutations in ACVRL1 or ENG, which encode proteins that function in bone morphogenetic protein signaling. HHT prevalence is estimated at 1 in 5000 and is accordingly classified as rare. However, HHT is suspected to be underdiagnosed due to variable age of...

In Finland the frequency of isolated cleft palate (CP) is higher than that of isolated cleft lip with or without cleft palate (CL/P). This trend contrasts to that in other European countries but its genetic underpinnings are unknown. We performed a genome-wide association study for orofacial clefts, which include CL/P and CP, in the Finnish population. We identified rs570516915, a single nucleotide polymorphism that is highly enriched in Finns and Estonians, as being strongly associated with CP ...

Cleft lip and/or palate (CL/P) occur in approximately 1 in 700 live births in the United States. High hereditary rates (50-80%) of CL/P indicate a strong genetic cause. The concept of strong genetic causes has been well-demonstrated in previous studies such as GWAS studies that identified IRF6 for Van der Woode syndrome. Since the risk for genetic factors is strongly associated with CL/P, we hypothesized that RNA sequencing (RNA-seq) from CL/P patients may reveal enriched genes. Differential exp...

BackgroundDisturbances in the intricate processes that control craniofacial morphogenesis can result in birth defects, most common of which are orofacial clefts (OFCs). Nonsyndromic cleft lip (nsCL), one of the phenotypic forms amongst OFCs, has a non-random laterality presentation with the left side being affected twice as often compared to the right side. This study investigates the etiology of nsCL and the factors contributing to its laterality using a pair of monozygotic twins with mirror-im...

Several genome wide association studies (GWASs) of orofacial cleft have been conducted, however the majority of studies to date have restricted their analysis to non-syndromic cleft lip with/without cleft palate and have not analysed all orofacial clefts combined, or conversely, investigated heterogeneity between subtypes. We conducted a GWAS of orofacial clefts within 2,268 cases from the Cleft Collective and 7,913 population-based controls; we performed analyses of all orofacial clefts, plus 7...

X-linked adrenoleukodystrophy (ALD) is a peroxisomal metabolic disorder with a highly complex clinical presentation. ALD is caused by mutations in the ABCD1 gene, and is characterized by the accumulation of very long-chain fatty acids in plasma and tissues. Disease-causing mutations are loss of function mutations, with no prognostic value with respect to the clinical outcome of an individual. All male patients with ALD develop spinal cord disease and a peripheral neuropathy in adulthood, althou...

Microtia is a common congenital craniofacial malformation characterized by the partial or complete absence of the external ear structure. Despite its relatively high incidence, the pathogenesis of microtia remain poorly understood. In this study, we analyzed both single-cell and bulk RNA sequencing data from microtia cases and identified a population of COL1+HES1+ mesenchymal stem cell in perichondrium with significantly higher expression of the CRABP2 gene, a gene that encodes a nuclear transpo...

Low HDL-C is the most frequent dyslipidemia in Mexicans, but few studies have examined the underlying genetic basis. Moreover, few lipid-associated variants have been tested for coronary artery disease (CAD) in Hispanic populations. Here, we performed a GWAS for HDL-C levels in 2,183 Mexican individuals, identifying 7 loci, including three with genome-wide significance and containing the candidate genes CETP, ABCA1 and SIDT2. The SIDT2 missense Val636Ile variant was associated with HDL-C levels ...

OBJECTIVEVan der Woude Syndrome (VWS) classically presents with combinations of lip pits (LP) and orofacial clefts, with marked phenotypic discordance even amongst individuals carrying the same mutation. Such discordance suggests a possible role for epigenetic factors as phenotypic modifiers. Both IRF6, causal for 70% of VWS cases, and TP63 interact in a regulatory loop to coordinate epithelial proliferation and differentiation for palatogenesis. We hypothesize that differential DNA methylation ...

Non-syndromic cleft lip with or without cleft palate (NSCL/P) is a common birth defect, affecting approximately 1 in 700 births. NSCL/P has complex etiology including several known genes and environmental factors; however, known genetic risk variants only account for a small fraction of the heritability of NSCL/P. It is commonly suggested that gene-by-environment (GxE) interactions may help explain some of the "missing" heritability of NSCL/P. We conducted a genome-wide GxE interaction study in ...

As one of the most common structural birth defects, orofacial clefts (OFCs) have been studied for decades, and recent studies have demonstrated that there are genetic differences between the different phenotypic presentations of OFCs. However, the contribution of rare genetic variation genome-wide to different subtypes of OFCs has been understudied, with most studies focusing on common genetic variation or rare variation within targeted regions of the genome. Therefore, we used whole-genome sequ...

Non-syndromic orofacial clefts (NSOC) are common craniofacial birth defects, and result from both genetic and environmental factors. NSOC include three major sub-phenotypes: non-syndromic cleft lip with palate (NSCLP), non-syndromic cleft lip only (NSCLO) and non-syndromic cleft palate only (NSCPO), NSCLP and NSCLO are also sometimes grouped as non-syndromic cleft lip with or without cleft palate (NSCL/P) based on epidemiology. Currently known loci only explain a limited proportion of the herita...

ObjectivesNonsyndromic orofacial clefts (OFCs) involve complex genetic and environmental factors, with over 60 risk loci accounting for only a minority of estimated heritability and residing in non-coding regions with unclear functional relevance. We hypothesize that some genetic variants alter orofacial cleft risk by modifying DNA methylation (DNAm) at regulatory sequences essential for craniofacial development, acting as methylation quantitative trait loci (meQTLs). MethodsWe analyzed 10 well...

22q11.2 deletion syndrome (22q11DS) has an incidence of 1 in 4,000. Most cases occur de novo, but about 10-15% of cases are inherited. Features include congenital heart disease, cleft palate, developmental delay, and other characteristics that can vary even among family members. The presence of nuclear mitochondrial genes in the deleted region, and the requirement of mitochondrial function for proper embryonic development, suggests that intrafamilial variability in maternally transmitted 22q11DS...

Several lines of evidence suggest that normal-range facial features and nonsyndromic orofacial clefts (OFCs) exhibit a shared genetic basis. Approaches designed to leverage this relationship hold the possibility of revealing new OFC risk loci by boosting discovery power. To test this idea, we applied a pleiotropy-informed GWAS method (cFDR-GWAS) with summary statistics from large, independent European GWASs of normal facial shape (n=4,680; n=3,566) and nonsyndromic cleft lip with or without clef...

Cleft lip and palate (CLP) are complex congenital anomalies with multifactorial etiology and significant genetic heterogeneity. This study aimed to elucidate the genetic basis of nonsyndromic CLP in an Indian family, wherein phenotypically normal parents had three affected offspring, including monozygotic twins, all presenting with bilateral complete CLP. Whole exome sequencing (WES) identified a compound heterozygous haplotype in the TTN gene shared by all affected siblings. The paternal haplot...