Joubert syndrome-derived induced pluripotent stem cells show altered neuronal differentiation in vitro.

Joubert syndrome (JS) is a recessively inherited congenital ataxia characterized by hypotonia, psychomotor delay, abnormal ocular movements, intellectual disability, and a peculiar cerebellar and brainstem malformation, the "molar tooth sign." Over 40 causative genes have been reported, all encoding for proteins implicated in the structure or functioning of the primary cilium, a subcellular organelle widely present in embryonic and adult tissues. In this paper, we developed an in vitro neuronal differentiation model using patient-derived induced pluripotent stem cells (iPSCs), to evaluate possible neurodevelopmental defects in JS. To this end, iPSCs from four JS patients harboring mutations in distinct JS genes (AHI1, CPLANE1, TMEM67, and CC2D2A) were differentiated alongside healthy control cells to obtain mid-hindbrain precursors and cerebellar granule cells. Differentiation was monitored over 31 days through the detection of lineage-specific marker expression by qRT-PCR, immunofluorescence, and transcriptomics analysis. All JS patient-derived iPSCs, regardless of the mutant gene, showed a similar impairment to differentiate into mid-hindbrain and cerebellar granule cells when compared to healthy controls. In addition, analysis of primary cilium count and morphology showed notable ciliary defects in all differentiating JS patient-derived iPSCs compared to controls. These results confirm that patient-derived iPSCs are an accessible and relevant in vitro model to analyze cellular phenotypes connected to the presence of JS gene mutations in a neuronal context.

Novel phenotype associated with homozygous likely pathogenic variant in the POP1 gene.

The biallelic variants of the POP1 gene are associated with the anauxetic dysplasia (AAD OMIM 607095), a rare skeletal dysplasia, characterized by prenatal rhizomelic shortening of limbs and generalized joint hypermobility. Affected individuals usually have normal neurodevelopmental milestones. Here we present three cases from the same family with likely pathogenic homozygous POP1 variant and a completely novel phenotype: a girl with global developmental delay and autism, microcephaly, peculiar dysmorphic features and multiple congenital anomalies. Two subsequent pregnancies were terminated due to multiple congenital malformations. Fetal DNA samples revealed the same homozygous variant in the POP1 gene. Expression of the RMRP was reduced in the proband compared with control and slightly reduced in both heterozygous parents, carriers for this variant. To our knowledge, this is the first report of this new phenotype, associated with a novel likely pathogenic variant in POP1. Our findings expand the phenotypic spectrum of POP1-related disorders.

Clinical and molecular characteristics of 26 fetuses with lethal multiple congenital contractures.

Multiple congenital contractures (MCC) due to fetal akinesia manifest across a broad spectrum of diseases, ranging from mild distal arthrogryposis to lethal fetal akinesia deformation sequence. We hereby present a series of 26 fetuses displaying severe MCC phenotypes from 18 families and describe detailed prenatal ultrasound findings, postmortem clinical evaluations, and genetic investigations. Most common prenatal findings were abnormal facial profile (65%), central nervous system abnormalities (62%), polyhydramnios (50%), increased nuchal translucency (50%), and fetal hydrops (35%). Postmortem examinations unveiled additional anomalies including facial dysmorphisms, dysplastic skeletal changes, ichthyosis, multiple pterygia, and myopathy, allowing preliminary diagnosis of particular Mendelian disorders in multiple patients. Evaluation of the parents revealed maternal grip myotonia in one family. By exome sequencing and targeted testing, we identified causative variants in ACTC1, CHST14, COG6, DMPK, DOK7, HSPG2, KLHL7, KLHL40, KIAA1109, NEB, PSAT1, RAPSN, USP14, and WASHC5 in 15 families, and one patient with a plausible diagnosis associated with biallelic NEB variants. Three patients received a dual diagnosis. Pathogenic alterations in newly discovered genes or in previously known genes recently linked to new MCC phenotypes were observed in 44% of the cohort. Our results provide new insights into the clinical and molecular landscape of lethal MCC phenotypes.

ARID2, a milder cause of Coffin-Siris Syndrome? Broadening the phenotype with 17 additional individuals.

Coffin-Siris Syndrome (CSS, MIM 135900) is now a well-described genetic condition caused by pathogenic variants in the Bromocriptine activating factor (BAF) complex, including ARID1B, ARID1A, ARID2, SMARCA4, SMARCE1, SMARCB1, SOX11, SMARCC2, DPF2, and more recently, BICRA. Individuals with CSS have a spectrum of various medical challenges, most often evident at birth, including feeding difficulties, hypotonia, organ-system anomalies, and learning and developmental differences. The classic finding of fifth digit hypo- or aplasia is seen variably. ARID2, previously described, is one of the less frequently observed gene changes in CSS. Although individuals with ARID2 have been reported to have classic features of CSS including hypertrichosis, coarse facial features, short stature, and fifth digit anomalies, as with many of the other CSS genes, there appears to be a spectrum of phenotypes. We report here a cohort of 17 individuals with ARID2 variants from the Coffin-Siris/BAF clinical registry and detail their medical challenges as well as developmental progress. Feeding difficulties, hypotonia, and short stature occur often, and hip dysplasia appears to occur more often than with other genes, however more severe medical challenges such as significant brain and cardiac malformations are rarer. Individuals appear to have mild to moderate intellectual impairment and may carry additional diagnoses such as ADHD. Further phenotypic description of this gene will aid clinicians caring for individuals with this rarer form of CSS.

Capillary malformations in a child caused by a novel HRAS mutation.

A 6-year-old boy with multiple capillary malformations of the port-wine birthmark (PWB) type on the right leg since birth presented with a varicose vein and segmental overgrowth of the affected leg. Genetic testing on affected skin confirmed the presence of a somatic novel pathogenic HRAS 30 bp in-frame duplication/insertion in the switch II domain. This case illustrates the phenotypic overlap of different genotypes and shows that somatic HRAS pathogenic variants, especially in-frame duplications/insertions, must be added to the list of the underlying causes in capillary malformations.

Non-syndromic Retinal Degeneration Caused by Pathogenic Variants in Joubert Syndrome Genes.

Inherited retinal degenerations (IRDs) are a group of genetic disorders characterized by progressive dysfunction and loss of photoreceptors. IRDs are classified as non-syndromic or syndromic, depending on whether retinal degeneration manifests alone or in combination with other associated symptoms. Joubert syndrome (JBTS) is a genetically and clinically heterogeneous disorder affecting the central nervous system and other organs and tissues, including the neuroretina. To date, 39 genes have been associated with JBTS, a majority of which encode structural or functional components of the primary cilium, a specialized sensory organelle present in most post-mitotic cells, including photoreceptors. The use of whole exome and IRD panel next-generation sequencing in routine diagnostics of non-syndromic IRD cases led to the discovery of pathogenic variants in JBTS genes that cause photoreceptor loss without other syndromic features. Here, we recapitulate these findings, describing the JBTS gene defects leading to non-syndromic IRDs.

Unmasking the challenges of Kabuki syndrome in adulthood: A case series.

Kabuki syndrome is a recognizable Mendelian disorder characterized by the clinical constellation of childhood hypotonia, developmental delay or intellectual impairment, and characteristic dysmorphism resulting from monoallelic pathogenic variants in KMT2D or KDM6A. In the medical literature, most reported patients are children, and data is lacking on the natural history of the condition across the lifespan, with little known about adult-specific presentations and symptoms. Here, we report the results of a retrospective chart review of eight adult patients with Kabuki syndrome, seven of whom are molecularly confirmed. We use their trajectories to highlight the diagnostic challenges unique to an adult population, expand on neurodevelopmental/psychiatric phenotypes across the lifespan, and describe adult-onset medical complications, including a potential cancer risk and unusual and striking premature/accelerated aging phenotype.

X-linked pyruvate dehydrogenase complex deficiency due to a novel PDHA1 variant associated with structural brain abnormalities in a fetus.

We report a case of pyruvate dehydrogenase E1 alpha subunit deficiency associated with a novel hemizygous PDHA1 variant presenting prenatally as multiple structural brain abnormalities in a male fetus. A healthy Finnish couple was initially referred to the Fetomaternal Medical Center because of suspected fetal choroid plexus cyst at 11 + 2 weeks of pregnancy. At 20 + 0 weeks, multiple abnormalities were observed with ultrasound including narrow thorax, slightly enlarged heart, hypoplastic cerebellum, absent cerebellar vermis and ventriculomegaly. Autopsy and genetic analyses were performed after the termination of pregnancy. The findings of macroscopic examination included cleft palate, abnormally overlapping position of fingers and toes and dysmorphic facial features. Neuropathological examination confirmed the absence of corpus callosum, cerebellar hypoplasia and ventriculomegaly. Nodular neuronal heterotopia was also observed. Trio exome sequencing revealed a novel hemizygous de novo variant c.1144C>T p.(Gln382*) in the PDHA1 gene, classified as likely pathogenic. We suggest that inherited metabolic disorders should be kept in mind as differential diagnoses in fetuses with structural brain abnormalities.

Keratosis pilaris: an update and approach to management.

Keratosis pilaris (KP) is a common, hyperkeratotic skin condition characterized by small, folliculocentric papules with variable perifollicular erythema. We provide an updated review on the pathogenesis, clinical manifestations, and management of this common, and often annoying, finding. KP represents a family of follicular disorders, of which KP simplex is by far the most common. Other variants and rare subtypes include keratosis pilaris rubra, erythromelanosis follicularis faciei et colli, and the spectrum of keratosis pilaris atrophicans. Inherited mutations of the FLG gene and ABCA12 gene have been implicated etiologically. KP may be associated with ichthyosis vulgaris and palmar hyperlinearity, but less likely atopic dermatitis. Some potential differential diagnoses for KP include lichen spinulosus, phrynoderma, ichthyosis vulgaris, and trichostasis spinulosa. General cutaneous measures such as hydrating skin, avoiding long baths or showers, and using mild soaps or cleansers should be recommended. Topical keratolytic agents are first-line therapy, followed by topical retinoids and corticosteroids. Recent options include a variety of lasers and microdermabrasion if the patient is refractory to topical therapy.

Using in vivo cerebellar electroporation to study neuronal cell proliferation and differentiation in a Joubert syndrome mouse model.

Joubert syndrome (JS) is an autosomal recessive ciliopathy that mainly affects the morphogenesis of the cerebellum and brain stem. To date, mutations in at least 39 genes have been identified in JS; all these gene-encoding proteins are involved in the biogenesis of the primary cilium and centrioles. Recent studies using the mouse model carrying deleted or mutated JS-related genes exhibited cerebellar hypoplasia with a reduction in neurogenesis; however, investigating specific neuronal behaviors during their development in vivo remains challenging. Here, we describe an in vivo cerebellar electroporation technique that can be used to deliver plasmids carrying GFP and/or shRNAs into the major cerebellar cell type, granule neurons, from their progenitor state to their maturation in a spatiotemporal-specific manner. By combining this method with cerebellar immunostaining and EdU incorporation, these approaches enable the investigation of the cell-autonomous effect of JS-related genes in granule neuron progenitors, including the pathogenesis of ectopic neurons and the defects in neuronal differentiation. This approach provides information toward understanding the multifaceted roles of JS-related genes during cerebellar development in vivo.

Bilateral Intraorbital Opticmeningoceles in Joubert Syndrome.

Congenital opticmeningoceles was the term coined to describe large pseudocystic lesions of the intraorbital segment of the optic nerve. This extremely rare congenital anomaly was reported unilaterally only in nonsyndromic patients with fully developed eyes. The authors describe here a 10-month-old girl with a previous diagnosis of Joubert syndrome who presented with the same type of optic nerve malformation in OU. Molecular genetic analysis disclosed a pathogenic variant of the TMEM67 gene which is associated with various types of ciliopathies.

A novel 1.38-kb deletion combined with a single nucleotide variant in KIAA0586 as a cause of Joubert syndrome.

BACKGROUND: KIAA0586, also known as Talpid3, plays critical roles in primary cilia formation and hedgehog signaling in humans. Variants in KIAA0586 could cause some different ciliopathies, including Joubert syndrome (JBTS), which is a clinically and genetically heterogeneous group of autosomal recessive neurological disorders. METHODS AND RESULTS: A 9-month-old girl was diagnosed as JBTS by the "molar tooth sign" of the mid-brain and global developmental delay. By whole-exome sequencing, we identified a single nucleotide variant c.3303G > A and a 1.38-kb deletion in KIAA0586 in the proband. These two variants of KIAA0586 were consistent with the mode of autosomal recessive inheritance in the family, which was verified using Sanger sequencing. CONCLUSIONS: This finding of a compound heterozygote with a 1.38-kb deletion and c.3303G > A gave a precise genetic diagnosis for the patient, and the novel 1.38-kb deletion also expanded the pathogenic variation spectrum of JBTS caused by KIAA0586.

Potter Deformation Sequence Caused by 17q12 Deletion: A Lethal Constellation.

17q12 deletion syndrome causes developmental abnormalities of the kidneys, pancreas, genital tract, and neurodevelopment, and it has a wide range of phenotypes ranging from fetal demise to normal adulthood with minimal renal impairment. Here we describe a rare case of 17q12 deletion diagnosed prenatally, complicated by anhydramnios and Potter sequence. The baby was born but necessitated life-saving interventions due to pulmonary and renal insufficiency and ultimately succumbed to multi-organ failure. We present full autopsy results describing findings linked to 17q12 deletion, including severe bilateral multicystic renal dysplasia, pancreatic hypoplasia, and cysts adjacent to the Fallopian tubes. We also describe pulmonary hypoplasia and Potter facies as consequences of anhydramnios. We correlate these findings to our current understanding of molecular signals altered by 17q12 deletion, notably affecting HNF1B and LHX1 genes, which are known to mediate renal and genitourinary tract development.

Further characterization of NFIB-associated phenotypes: Report of two new individuals.

Nuclear Factor I B (NFIB) haploinsufficiency has recently been identified as a cause of intellectual disability (ID) and macrocephaly. Here we report on two new individuals carrying a microdeletion in the chromosomal region 9p23-p22.3 containing NFIB. The first is a 7-year 9-month old boy with developmental delays, ID, definite facial anomalies, and brain and spinal cord magnetic resonance imaging findings including periventricular nodular heterotopia, hypoplasia of the corpus callosum, arachnoid cyst in the left middle cranial fossa, syringomyelia in the thoracic spinal cord and distal tract of the conus medullaris, and a stretched appearance of the filum terminale. The second is a 32-year-old lady (the proband' mother) with dysmorphic features, and a history of learning disability, hypothyroidism, poor growth, left inguinal hernia, and panic attacks. Her brain magnetic resonance imaging findings include a dysmorphic corpus callosum, and a small cyst in the left choroidal fissure that marks the hippocampal head. Array-based comparative genomic hybridization identified, in both, a 232 Kb interstitial deletion at 9p23p22.3 including several exons of NFIB and no other known genes. Our two individuals add to the knowledge of this rare disorder through the addition of new brain and spinal cord MRI findings and dysmorphic features. We propose that NFIB haploinsufficiency causes a clinically recognizable malformation-ID syndrome.

Molecular characterization of an embryonal rhabdomyosarcoma occurring in a patient with Kabuki syndrome: report and literature review in the light of tumor predisposition syndromes.

Kabuki syndrome is a well-recognized syndrome characterized by facial dysmorphism and developmental delay/intellectual disability and in the majority of patients a germline variant in KMT2D is found. As somatic KMT2D variants can be found in 5-10% of tumors a tumor predisposition in Kabuki syndrome is discussed. So far less than 20 patients with Kabuki syndrome and a concomitant malignancy have been published. Here we report on a female patient with Kabuki syndrome and a c.2558_2559delCT germline variant in KMT2D who developed an embryonal rhabdomyosarcoma (ERMS) at 10 years. On tumor tissue we performed DNA-methylation profiling and exome sequencing (ES). Copy number analyses revealed aneuploidies typical for ERMS including (partial) gains of chromosomes 2, 3, 7, 8, 12, 15, and 20 and 3 focal deletions of chromosome 11p. DNA methylation profiling mapped the case to ERMS by a DNA methylation-based sarcoma classifier. Sequencing suggested gain of the wild-type KMT2D allele in the trisomy 12. Including our patient literature review identified 18 patients with Kabuki syndrome and a malignancy. Overall, the landscape of malignancies in patients with Kabuki syndrome was reminiscent of that of the pediatric population in general. Histopathological and molecular data were only infrequently reported and no report included next generation sequencing and/or DNA-methylation profiling. Although we found no strong arguments pointing towards KS as a tumor predisposition syndrome, based on the small numbers any relation cannot be fully excluded. Further planned studies including profiling of additional tumors and long term follow-up of KS-patients into adulthood could provide further insights.

New insights into CC2D2A-related Joubert syndrome.

PURPOSE: In this study, we describe the phenotype and genotype of the largest cohort of patients with Joubert syndrome (JS) carrying pathogenic variants on one of the most frequent causative genes, CC2D2A. METHODS: We selected 53 patients with pathogenic variants on CC2D2A, compiled and analysed their clinical, neuroimaging and genetic information and compared it to previous literature. RESULTS: Developmental delay (motor and language) was nearly constant but patients had normal intellectual efficiency in 74% of cases (20/27 patients) and 68% followed mainstream schooling despite learning difficulties. Epilepsy was found in only 13% of cases. Only three patients had kidney cysts, only three had genuine retinal dystrophy and no subject had liver fibrosis or polydactyly. Brain MRIs showed typical signs of JS with rare additional features. Genotype-phenotype correlation findings demonstrate a homozygous truncating variant p.Arg950* linked to a more severe phenotype. CONCLUSION: This study contradicts previous literature stating an association between CC2D2A-related JS and ventriculomegaly. Our study implies that CC2D2A-related JS is linked to positive neurodevelopmental outcome and low rate of other organ defects except for homozygous pathogenic variant p.Arg950*. This information will help modulate patient follow-up and provide families with accurate genetic counselling.

Síndrome del incisivo central maxilar medio único en neonato / Solitary median maxillary central incisor syndrome in neonates / Síndrome do incisivo central maxilar médio solitário em neonatos

Introducción: el síndrome del incisivo central maxilar medio único (SMMCI) es un trastorno de etiología desconocida, con base genética heterogénea, que se caracteriza por la erupción de un único incisivo central en el maxilar y que se puede relacionar con multitud de patologías y síndromes, entre los que destacan las alteraciones de la línea media, obstrucción nasal congénita, disfunción hipofisaria, talla baja y holoprosencefalia. Caso clínico: neonato mujer con síndrome dismórfico no filiado y obstrucción nasal congénita, que es diagnosticada de SMMCI tras consultar en repetidas ocasiones por cuadros de dificultad respiratoria y problemas para alimentarse. Conclusiones: el conocimiento de este raro síndrome es fundamental para la realización de un diagnóstico precoz por parte del equipo pediátrico y obstétrico, ya que un diagnóstico temprano es posible, mejorando la evaluación prenatal ecográfica, así como el adecuado manejo posnatal multidisciplinar posterior de nuestros pacientes.

Introduction: the Solitary Median Maxillary Central Incisor Syndrome (SMMCI) is a disorder of unknown etiology, with a heterogeneous genetic basis, characterized by the eruption of a single central incisor in the maxilla and that can be linked to various pathologies and syndromes, among which the alterations of the midline, congenital nasal obstruction, pituitary dysfunction, short stature and holoprosencephaly stand out. Clinical case: female newborns with unknown dysmorphic syndrome and congenital nasal obstruction, diagnosed with SMMCI after repeated consultations due to respiratory distress and feeding problems. Conclusions: understanding this rare syndrome is essential for an early diagnosis to be carried out by the pediatric and obstetric team, since it will improve the ultrasound prenatal assessment, as well as the adequate subsequent multidisciplinary postnatal patient management procedures.

Introdução: a síndrome do incisivo central maxilar médio solitário (SICMMS) é uma desordem de etiologia desconhecida, com base genética heterogênea, caracterizada pela erupção de um único incisivo central na maxila e que pode estar relacionada a uma infinidade de patologias e síndromes. onde se destacam alterações da linha média, obstrução nasal congênita, disfunção hipofisária, baixa estatura e holoprosencefalia. Caso clínico: recém-nascida com síndrome dismórfica de origem desconhecida e obstrução nasal congênita, diagnosticada com SICMSS após várias consultas por desconforto respiratório e problemas de alimentação. Conclusões: o conhecimento desta rara síndrome é essencial para que a equipe pediátrica e obstétrica possa fazer um diagnóstico precoce, pois ele pode melhorar a avaliação ultrassonográfica pré-natal, bem como o adequado manejo pós-natal multidisciplinar pós-natal dos pacientes.

Biallelic Variants in CCDC39 Gene Lead to Primary Ciliary Dyskinesia and Kartagener Syndrome.

Background: Primary ciliary dyskinesia (PCD) is a clinical syndrome characterized by cilia with an abnormal structure or function. Its main clinical manifestations comprise chronic bronchitis, cough, recurrent respiratory infections, situs inversus, and male infertility. Single-gene variants are widely assumed to be the main cause of this rare disease, and more than 40 genes have been described to be associated with its onset. CCDC39 is essential for assembling the inner dynein arms and dynein regulatory complex and is important in cilia motility. CCDC39 variants were reported as a monogenic etiology of PCD. Methods: This study investigated two unrelated Chinese patients diagnosed as PCD. The chest computed tomography scan was performed to identify PCD phenotypes of the two probands. Considering the effect of PCD on male fertility, routine semen analysis, sperm morphology examination, and scanning electron microscopy were performed to assess the semen characteristics of male proband in family 2 (F2 II-1), who had a history of infertility. Subsequently, the peripheral blood samples of probands were collected to perform whole-exome sequencing (WES) to explore the possible genetic causes of this disease. Results: Whole-exome sequencing revealed a homozygous CCDC39 variant in the female proband of family 1 (F1 II-1: c.286C>T:p.Arg96Ter) and two compound heterozygous CCDC39 variants in the male proband of family 2 (F2 II-1: c.732_733del: p.Ala245PhefsTer18; c.2800_2802dup:p.Val934dup). The two probands showed the typical PCD phenotypes, including chronic bronchitis, recurrent respiratory infections, and situs inversus. The male proband also showed oligoasthenoteratospermia with multiple morphological abnormalities of the sperm flagella. Additionally, CCDC39 protein level was significantly lower in the sperm of male proband than in the sperm from normal controls. Conclusion: We identified a homozygous variant reported previously and two compound heterozygous variants of CCDC39 possibly responsible for PCD pathogenesis, expanding the variant spectrum of Chinese PCD, Kartagener syndrome, and morphological abnormalities of the sperm flagella involving CCDC39.

Attention to renal involvement: report of 17 Joubert syndrome cases in children of a single center in China.

BACKGROUND: Joubert Syndrome (JS) is a rare genetic developmental disorder. We are aiming for increasing awareness of this disease especially kidney involvement in children with JS. METHODS: Clinical and genetic data of 17 cases of JS in Beijing children's hospital in the past 21 years were collected retrospectively. RESULTS: Twelve males and 5 females, aged from 12d to 15y8m. The most common involvement was neurological system involvement. The second most common involvement was renal involvement: end stage kidney disease in 6 cases (35%), hematuria in 5 cases (29%), proteinuria in 5 cases (29%), renal diffuse lesions in 4 cases (24%), renal cystic lesions in 2 cases (12%), and echogenic enhancement of parenchyma in 2 cases (12%). 10 cases did genetic tests. 3 cases with renal deficiency all had RPGRIP1L gene mutation. CONCLUSIONS: The most common involvement of JS is neurological involvement, and the second is renal involvement. Pediatricians should improve awareness of JS and conduct systemic evaluation of children. More attention should be paid to renal involvement which may be onset hidden but fatal. Early recognition and diagnosis are the goals to delay the start to dialysis and improve quality of patients' life. The RPGRIP1L gene mutation maybe the most common gene mutation in JS and may have correlations with renal involvement.

The Joubert-Meckel-Nephronophthisis Spectrum of Ciliopathies.

The Joubert syndrome (JS), Meckel syndrome (MKS), and nephronophthisis (NPH) ciliopathy spectrum could be the poster child for advances and challenges in Mendelian human genetics over the past half century. Progress in understanding these conditions illustrates many core concepts of human genetics. The JS phenotype alone is caused by pathogenic variants in more than 40 genes; remarkably, all of the associated proteins function in and around the primary cilium. Primary cilia are near-ubiquitous, microtubule-based organelles that play crucial roles in development and homeostasis. Protruding from the cell, these cellular antennae sense diverse signals and mediate Hedgehog and other critical signaling pathways. Ciliary dysfunction causes many human conditions termed ciliopathies, which range from multiple congenital malformations to adult-onset single-organ failure. Research on the genetics of the JS-MKS-NPH spectrum has spurred extensive functional work exploring the broadly important role of primary cilia in health and disease. This functional work promises to illuminate the mechanisms underlying JS-MKS-NPH in humans, identify therapeutic targets across genetic causes, and generate future precision treatments.