SMC1A epilepsy syndrome: clinical data from a large international cohort.

SMC1A epilepsy syndrome or developmental and epileptic encephalopathy-85 with or without midline brain defects (DEE85, OMIM #301044) is an X-linked neurologic disorder associated with mutations of the SMC1A gene, which is also responsible for about 5% of patients affected by Cornelia de Lange syndrome spectrum (CdLS). Only described in female patients, SMC1A epilepsy syndrome is characterized by the onset of severe refractory epileptic seizures in the first year of life, global developmental delay, a variable degree of intellectual disability, and dysmorphic facial features not typical of CdLS. This was a descriptive observational study for the largest international cohort with this specific disorder. The main goal of this study was to improve the knowledge of the natural history of this phenotype with particular attention to the psychomotor development and the epilepsy data. The analyzed cohort shows normal prenatal growth with the subsequent development of postnatal microcephaly. The incidence of neonatal problems (seizures and respiratory compromise) is considerable (51.4%). There is a significant prevalence of central nervous system (20%) and cardiovascular malformations (20%). Motor skills are generally delayed. The presence of drug-resistant epilepsy is confirmed; the therapeutic role of a ketogenic diet is still uncertain. The significant regression of previously acquired skills following the onset of seizures has been observed. Facial dysmorphisms are variable and no patient shows a classic CdLS phenotype. To sum up, SMC1A variants caused drug-resistant epilepsy in these patients, more than two-thirds of whom were shown to progress to developmental and epileptic encephalopathy. The SMC1A gene variants are all different from each other (apart from a couple of monozygotic twins), demonstrating the absence of a mutational hotspot in the SMC1A gene. Owing to the absence of phenotypic specificity, whole-exome sequencing is currently the diagnostic gold standard.

Application of the Face2Gene tool in an Italian dysmorphological pediatric clinic: Retrospective validation and future perspectives.

Neurodevelopmental disorders exhibit recurrent facial features that can suggest the genetic diagnosis at a glance, but recognizing subtle dysmorphisms is a specialized skill that requires very long training. Face2Gene (FDNA Inc) is an innovative computer-aided phenotyping tool that analyses patient's portraits and suggests 30 candidate syndromes with similar morphology in a prioritized list. We hypothesized that the software could support even expert physicians in the diagnostic workup of genetic conditions. In this study, we assessed the performance of Face2Gene in an Italian dysmorphological pediatrics clinic. We uploaded two-dimensional face pictures of 145 children affected by genetic conditions with typical phenotypic traits. All diagnoses were previously confirmed by cytogenetic or molecular tests. Overall, the software's differential included the correct syndrome in most cases (98%). We evaluated the efficiency of the algorithm even considering the rareness of the genetic conditions. All "common" diagnoses were correctly identified, most of them with high diagnostic accuracy (93% in top-3 matches). Finally, the performance for the most common pediatric syndromes was calculated. Face2Gene performed well even for ultra-rare genetic conditions (75% within top-3 matches and 83% within top-10 matches). Expert geneticists maybe do not need computer support to recognize common syndromes, but our results prove that the tool can be useful not only for general pediatricians but also in dysmorphological clinics for ultra-rare genetic conditions.

Comparison of first-tier whole-exome sequencing with a multi-step traditional approach for diagnosing paediatric outpatients: An Italian prospective study.

BACKGROUND: The recent guidelines suggest the use of genome-wide analyses, such as whole exome sequencing (WES), at the beginning of the diagnostic approach for cases with suspected genetic conditions. However, in many realities it still provides for the execution of a multi-step pathway, thus requiring several genetic tests to end the so-called 'diagnostic odyssey'. METHODS: We reported the results of GENE Project (Genomic analysis Evaluation NEtwork): a multicentre prospective cohort study on 125 paediatric outpatients with a suspected genetic disease in which we performed first-tier trio-WES, including exome-based copy number variation analysis, in parallel to a 'traditional approach' of two/three sequential genetic tests. RESULTS: First-tier trio-WES detected a conclusive diagnosis in 41.6% of patients, way above what was found with routine genetic testing (25%), with a time-to-result of about 50 days. Notably, the study showed that 44% of WES-reached diagnoses would be missed with the traditional approach. The diagnostic rate (DR) of the two approaches varied in relation to the phenotypic class of referral and to the proportion of cases with a defined diagnostic suspect, proving the major difference for neurodevelopmental disorders. Moreover, trio-WES analysis detected variants in candidate genes of unknown significance (EPHA4, DTNA, SYNCRIP, NCOR1, TFDP1, SPRED3, EDA2R, PHF12, PPP1R12A, WDR91, CDC42BPG, CSNK1D, EIF3H, TMEM63B, RIPPLY3) in 19.4% of undiagnosed cases. CONCLUSION: Our findings represent real-practice evidence of how first-tier genome-wide sequencing tests significantly improve the DR for paediatric outpatients with a suspected underlying genetic aetiology, thereby allowing a time-saving setting of the correct management, follow-up and family planning.

FOXI3 pathogenic variants cause one form of craniofacial microsomia.

Craniofacial microsomia (CFM; also known as Goldenhar syndrome), is a craniofacial developmental disorder of variable expressivity and severity with a recognizable set of abnormalities. These birth defects are associated with structures derived from the first and second pharyngeal arches, can occur unilaterally and include ear dysplasia, microtia, preauricular tags and pits, facial asymmetry and other malformations. The inheritance pattern is controversial, and the molecular etiology of this syndrome is largely unknown. A total of 670 patients belonging to unrelated pedigrees with European and Chinese ancestry with CFM, are investigated. We identify 18 likely pathogenic variants in 21 probands (3.1%) in FOXI3. Biochemical experiments on transcriptional activity and subcellular localization of the likely pathogenic FOXI3 variants, and knock-in mouse studies strongly support the involvement of FOXI3 in CFM. Our findings indicate autosomal dominant inheritance with reduced penetrance, and/or autosomal recessive inheritance. The phenotypic expression of the FOXI3 variants is variable. The penetrance of the likely pathogenic variants in the seemingly dominant form is reduced, since a considerable number of such variants in affected individuals were inherited from non-affected parents. Here we provide suggestive evidence that common variation in the FOXI3 allele in trans with the pathogenic variant could modify the phenotypic severity and accounts for the incomplete penetrance.

Patients with DeSanto-Shinawi syndrome: Further extension of phenotype from Italy.

Here we describe three patients with neurodevelopmental disorders characterized by mild-to-moderate intellectual disability, mildly dysmorphic features, and hirsutism, all of which carry de novo sequence variants in the WW domain-containing adaptor of the coiled-coil (WAC) gene; two of these-c.167delA, p.(Asn56I1efs*136) and c.1746G>C, p.(Gln582His)-are novel pathogenic variants, and the third-c.1837C>T, p(Arg613*)-has been previously described. Diseases associated with WAC include DeSanto-Shinawi syndrome; to date, de novo heterozygous constitutional pathogenic WAC variants have caused a syndromic form of intellectual disability and mild dysmorphic features in 33 patients, yet potential associations with other clinical manifestations, such as oligomenorrhea and hyperandrogenism, remain unknown, because the phenotypic spectrum of the condition has not yet been delineated. The patient bearing the novel c.167delA WAC gene variant presented a normal psychomotor development, oligomenorrhea, hyperandrogenism, and hirsutism, and hirsutism was also observed in the patient with the c.1746G>C WAC gene variant. Hypertrichosis and hirsutism have been described in nine DeSanto-Shinawi patients, only in 17 of the 33 aforementioned patients thus far reported this aspect, and no hormonal-pattern data are available. In conclusion, we note that the pathogenic c.167delA WAC variant may be associated with a mild phenotype; and in addition to the neurodevelopmental problems nearly all DeSanto-Shinawi patients experience (i.e., intellectual disability and/or developmental delay), we recommend the addition of mild dysmorphic features, hirsutism, and hypertrichosis to this clinical presentation.

Expanding the Molecular Spectrum of ANKRD11 Gene Defects in 33 Patients with a Clinical Presentation of KBG Syndrome.

KBG syndrome (KBGS) is a neurodevelopmental disorder caused by the Ankyrin Repeat Domain 11 (ANKRD11) haploinsufficiency. Here, we report the molecular investigations performed on a cohort of 33 individuals with KBGS clinical suspicion. By using a multi-testing genomic approach, including gene sequencing, Chromosome Microarray Analysis (CMA), and RT-qPCR gene expression assay, we searched for pathogenic alterations in ANKRD11. A molecular diagnosis was obtained in 22 out of 33 patients (67%). ANKRD11 sequencing disclosed pathogenic or likely pathogenic variants in 18 out of 33 patients. CMA identified one full and one terminal ANKRD11 pathogenic deletions, and one partial duplication and one intronic microdeletion, with both possibly being pathogenic. The pathogenic effect was established by RT-qPCR, which confirmed ANKRD11 haploinsufficiency only for the three deletions. Moreover, RT-qPCR applied to six molecularly unsolved KBGS patients identified gene downregulation in a clinically typical patient with previous negative tests, and further molecular investigations revealed a cryptic deletion involving the gene promoter. In conclusion, ANKRD11 pathogenic variants could also involve the regulatory regions of the gene. Moreover, the application of a multi-test approach along with the innovative use of RT-qPCR improved the diagnostic yield in KBGS suspected patients.

A missense mutation in DDRGK1 gene associated to Shohat-type spondyloepimetaphyseal dysplasia: Two case reports and a review of literature.

Spondylo-epi-metaphyseal dysplasia Shohat type (SEMDSH, OMIM # 602557) is a rare skeletal dysplasia. Until recently, only eight patients of five families have been reported. The disorder is characterized by severely disproportionate short stature with a short neck, small trunk with abdominal distension, and short lower limbs. Joint laxity and bowed legs are seen. The same homozygous splicing pathogenic variant in the DDRGK1 gene was found in four Iraqi families. Here we report a homozygous missense pathogenic variant in DDRGK1 in two children from unrelated two Moroccan families. The clinical and radiological phenotypes of the affected children were similar to those previously described.

Cantù syndrome: Report of a patient with a novel variant in KCNJ8 and revision of literature.

Cantù syndrome (CS) is a rare multisystemic disorder, characterized by congenital hypertrichosis, macrocephaly, facial dysmorphisms, cardiomegaly, vascular, and skeletal anomalies. From the cognitive point of view, most of the patients show a mild speech delay and a few of them present intellectual disability and learning difficulties. To date, most CS-reported cases are caused by heterozygous ABCC9 gene mutations. Only three patients with CS and heterozygous KCNJ8 gene variants have been reported. The authors here present the fourth case of CS with a variant in KCNJ8 in a 6-month-old baby. Diagnosis was reached through Trio-Whole Exome analysis that revealed a de novo missense variant in KCNJ8.

Neuropsychiatric Functioning in CDLS: A Detailed Phenotype and Genotype Correlation.

Behavioural phenotype and autism-related traits of 38 patients affected by Cornelia de Lange syndrome (CdLS) were assessed using a specific neuropsychiatric protocol. Subsequently,we search for possible genotype-phenotype correlations comparing individuals with NIPBL variants and patients with negative molecular results. Firstly results showed a higher percentage of subjects with normal intellectual quotient (IQ) and borderline IQ; adaptive skills were lower than expected for age in all participants. 39.5% of the sample presented with autism spectrum disorder (ASD), NIPBL mutated individuals demonstrated a worse trend in comparison with the clinical diagnosis group. non-truncating individuals displayed no ASD and better communication abilities than truncating individuals. Findings increase our awareness of the strengths and weaknesses points in CdLS individuals.

Cornelia de Lange Syndrome: From a Disease to a Broader Spectrum.

Cornelia de Lange syndrome (CdLS) is a genetic disease that exemplifies the evolution of knowledge in the field of rare genetic disorders. Originally described as a unique pattern of major and minor anomalies, over time this syndrome has been shown to be characterized by a significant variability of clinical expression. By increasing the number of patients described, knowledge of the natural history of the condition has been enriched with the demonstration of the relative frequency of various potential comorbidities. Since 2006, the discovery of CdLS's molecular basis has shown an equally vast genetic heterogeneity linked to the presence of variants in genes encoding for the cohesin complex pathway. The most recent clinical-genetic data led to the classification of the "original syndrome" into a "clinical spectrum" that foresees the presence of classic patients, of non-classic forms, and of conditions that show a modest phenotypic overlapping with the original disease. Finally, the knowledge of the molecular basis of the disease has allowed the development of basic research projects that could lay the foundations for the development of possible innovative pharmacological treatments.

Clinical relevance of postzygotic mosaicism in Cornelia de Lange syndrome and purifying selection of NIPBL variants in blood.

Postzygotic mosaicism (PZM) in NIPBL is a strong source of causality for Cornelia de Lange syndrome (CdLS) that can have major clinical implications. Here, we further delineate the role of somatic mosaicism in CdLS by describing a series of 11 unreported patients with mosaic disease-causing variants in NIPBL and performing a retrospective cohort study from a Spanish CdLS diagnostic center. By reviewing the literature and combining our findings with previously published data, we demonstrate a negative selection against somatic deleterious NIPBL variants in blood. Furthermore, the analysis of all reported cases indicates an unusual high prevalence of mosaicism in CdLS, occurring in 13.1% of patients with a positive molecular diagnosis. It is worth noting that most of the affected individuals with mosaicism have a clinical phenotype at least as severe as those with constitutive pathogenic variants. However, the type of genetic change does not vary between germline and somatic events and, even in the presence of mosaicism, missense substitutions are located preferentially within the HEAT repeat domain of NIPBL. In conclusion, the high prevalence of mosaicism in CdLS as well as the disparity in tissue distribution provide a novel orientation for the clinical management and genetic counselling of families.

ANKRD11 variants: KBG syndrome and beyond.

Mutations affecting the transcriptional regulator Ankyrin Repeat Domain 11 (ANKRD11) are mainly associated with the multisystem developmental disorder known as KBG syndrome, but have also been identified in individuals with Cornelia de Lange syndrome (CdLS) and other developmental disorders caused by variants affecting different chromatin regulators. The extensive functional overlap of these proteins results in shared phenotypical features, which complicate the assessment of the clinical diagnosis. Additionally, re-evaluation of individuals at a later age occasionally reveals that the initial phenotype has evolved toward clinical features more reminiscent of a developmental disorder different from the one that was initially diagnosed. For this reason, variants in ANKRD11 can be ascribed to a broader class of disorders that fall within the category of the so-called chromatinopathies. In this work, we report on the clinical characterization of 23 individuals with variants in ANKRD11. The subjects present primarily with developmental delay, intellectual disability and dysmorphic features, and all but two received an initial clinical diagnosis of either KBG syndrome or CdLS. The number and the severity of the clinical signs are overlapping but variable and result in a broad spectrum of phenotypes, which could be partially accounted for by the presence of additional molecular diagnoses and distinct pathogenic mechanisms.

Burden of care in families of patients with rare genetic diseases: analysis of a large Italian cohort.

In the last decade, the number of children and youth with special health care needs (CYSHCN) is increased as a result of the improvement of neonatal and pediatric assistance. The aim of our study was to describe the burden of care of the families caring a CYSHCN in our country, evaluating their living condition in order to explore socio-economic characteristics, health problems, needs and their adaptation processes trying to reach a balance between the needs of the disabled child and those of the other family members. We administered a questionnaire to the parents of CYSHCN during a routine clinical evaluation. From the analyses of questionnaires obtained, parents were the main caregiver of the children and 43,8% of them reported that they were not getting enough support. Burden of care fell on parents and indeed compilers reported an average level of stress of 3,2 (0-5) and more important, the main reported sources of stress were the concern about the future and health of their children. From the analyses of our population emerged unsatisfied needs of these families and their necessity to be effectively supported and integrated into the social fabric of the community. Social supporting is essential to help managing family stress and is evident the needed of these parents for interventions to directly target caregiver needs through the provision of tailored services, such as respite care opportunity, peer support, financial aid and medical home technologies to improve their quality of life.

Maternal Uniparental Disomy of Chromosome 20 (UPD(20)mat) as Differential Diagnosis of Silver Russell Syndrome: Identification of Three New Cases.

Silver Russell Syndrome (SRS, MIM #180860) is a rare growth retardation disorder in which clinical diagnosis is based on six features: pre- and postnatal growth failure, relative macrocephaly, prominent forehead, body asymmetry, and feeding difficulties (Netchine-Harbison clinical scoring system (NH-CSS)). The molecular mechanisms consist in (epi)genetic deregulations at multiple loci: the loss of methylation (LOM) at the paternal H19/IGF2:IG-DMR (chr11p15.5) (50%) and the maternal uniparental disomy of chromosome 7 (UPD(7)mat) (10%) are the most frequent causes. Thus far, about 40% of SRS remains undiagnosed, pointing to the need to define the rare mechanisms in such a consistent fraction of unsolved patients. Within a cohort of 176 SRS with an NH-CSS ≥ 3, a molecular diagnosis was disclosed in about 45%. Among the remaining patients, we identified in 3 probands (1.7%) with UPD(20)mat (Mulchandani-Bhoj-Conlin syndrome, OMIM #617352), a molecular mechanism deregulating the GNAS locus and described in 21 cases, characterized by severe feeding difficulties associated with failure to thrive, preterm birth, and intrauterine/postnatal growth retardation. Our patients share prominent forehead, feeding difficulties, postnatal growth delay, and advanced maternal age. Their clinical assessment and molecular diagnostic flowchart contribute to better define the characteristics of this rare imprinting disorder and to rank UPD(20)mat as the fourth most common pathogenic molecular defect causative of SRS.

Lithium as a possible therapeutic strategy for Cornelia de Lange syndrome.

Cornelia de Lange Syndrome (CdLS) is a rare developmental disorder affecting a multitude of organs including the central nervous system, inducing a variable neurodevelopmental delay. CdLS malformations derive from the deregulation of developmental pathways, inclusive of the canonical WNT pathway. We have evaluated MRI anomalies and behavioral and neurological clinical manifestations in CdLS patients. Importantly, we observed in our cohort a significant association between behavioral disturbance and structural abnormalities in brain structures of hindbrain embryonic origin. Considering the cumulative evidence on the cohesin-WNT-hindbrain shaping cascade, we have explored possible ameliorative effects of chemical activation of the canonical WNT pathway with lithium chloride in different models: (I) Drosophila melanogaster CdLS model showing a significant rescue of mushroom bodies morphology in the adult flies; (II) mouse neural stem cells restoring physiological levels in proliferation rate and differentiation capabilities toward the neuronal lineage; (III) lymphoblastoid cell lines from CdLS patients and healthy donors restoring cellular proliferation rate and inducing the expression of CyclinD1. This work supports a role for WNT-pathway regulation of CdLS brain and behavioral abnormalities and a consistent phenotype rescue by lithium in experimental models.

Williams-Beuren Syndrome and celiac disease: A real association?

Celiac disease (CD) screening in patients with Williams-Beuren Syndrome (WBS) is suggested, although data described in literature are discordant regarding CD prevalence in WBS. We retrospectively collected data from 101 WBS Italian patients [mean age: 13.5 years], to clarify the CD prevalence in a large cohort. All patients underwent a CD biochemical screening: IgA and anti-transglutaminase reflex antibodies (tTGA). CD-specific HLA typing was available for 42 patients. Small intestinal biopsy was performed in patients according to ESPGHAN guidelines. In 7 WBS patients an overt celiac disease was diagnosed. In 3 patients CD was confirmed by symptoms, HLA-DQ heterodimers and CD specific antibodies title, whereas in 4 patients, it was confirmed by a small intestinal biopsy. CD prevalence in our cohort is 6.9% (7/101). In 42/101 patients the CD-specific HLA typing was available, detecting 29/42 (69%) patients genetically predisposed to CD. The CD prevalence and CD-specific HLA prevalence are both higher than in the general population (p < 0.001; p < 0.001). Our cohort is the most numerous described confirming that the CD risk in WBS patients is significantly greater than in general population. Moreover, our HLA typing results, as well as scientific literature, suggest that the higher CD prevalence in WBS patients might not be intrinsically related to the genetic disease itself but with the higher HLA prevalence. However, HLA typing should be performed in bigger WBS cohorts to confirm this hypothesis. Our data confirms that HLA typing is mandatory in WBS patients and that CD screening should be performed only if genetically predisposed.

Complex nutritional deficiencies in a large cohort of Italian patients with Cornelia de Lange syndrome spectrum.

Cornelia de Lange syndrome Spectrum (CdLSp) is characterized by intellectual disability, facial dysmorphisms, and growth impairment. Although eating difficulties are a well-known feature of the disease, there is no data regarding the nutritional deficiencies of these patients. The food intake was tracked using a dietary transcription provided by the family/caregivers, biochemical nutritional parameters were measured with laboratory tests and through an accurate clinical evaluation of the incidence of qualitative and quantitative imbalances in a cohort of 73 patients with CdLSp ware determined. Of these 73, 62 (85%) subjects provided a complete and detailed dietary transcription. In the studied population, a quantitative caloric imbalance in 47/62 (76%) subjects was observed. The caloric intake was low in 27/62 (43%) subjects whereas excessive in 20/62 (33%). Only 15/62 (24%) had an optimum caloric intake. Regarding micronutrients, a calcium intake deficiency in 32% of the patients (20/62) was observed. Blood tests revealed a low iron level in 22/73 (30%) of the patients and 25(OH)D deficiency in 49/73 (67%). Serum hypocalcemia was not evidenced. Qualitative and quantitative imbalances resulted in more frequent than expected in CdLSp patients. A qualitative imbalance was more prevalent in younger patients while in older patients prevailed mainly a quantitative disproportion. We found no statistically meaningful correlation between dietary imbalances, genetic, or clinical parameters. Our findings highlight the need for further studies to evaluate the basal metabolic rate of CdLSp patients and find a correlation with their growth impairment.

Nissen fundoplication in Cornelia de Lange syndrome spectrum: Who are the potential candidates?

Cornelia de Lange spectrum (CdLSp) is a rare genetic condition characterized by intellectual disability, facial dysmorphisms, major malformations, growth impairment, and development delay. Approximately 80% of CdLSp patients have gastroesophageal reflux disease (GERD) with a varied clinical presentation. The aim of this study is to define potential clinical/genetic risk factors based on the clinical phenotype description of CdLSp patients with severe GERD who underwent surgical treatment. We retrospectively collected data from 23 CdLSp patients, 13 females and 10 males. Mean age of the patients undergoing surgical treatment was of 4 years. 21/23 (91%) had a molecular characterization, of which 21/21 (100%) had a NIPBL gene mutation, while 2/23 (9%) did not have a genetical characterization, only a clinical diagnosis. Most of our patients presented a moderate-severe severity score (21/23, 91%) with limb malformations evidenced in 10/23 (44%) of our patients and a moderate-severe intellectual disability in 20/23 (87%). Therefore, CdLSp patients harboring NIPBL variants, upper limb malformations and severe psychomotor delay are more likely to suffer from severe GERD, not responsive to proton pump inhibitors treatment. These features should be considered as clinical markers for potentially severe GERD that might require surgical treatment.

De novo heterozygous missense and loss-of-function variants in CDC42BPB are associated with a neurodevelopmental phenotype.

CDC42BPB encodes MRCKß (myotonic dystrophy-related Cdc42-binding kinase beta), a serine/threonine protein kinase, and a downstream effector of CDC42, which has recently been associated with Takenouchi-Kosaki syndrome, an autosomal dominant neurodevelopmental disorder. We identified 12 heterozygous predicted deleterious variants in CDC42BPB (9 missense, 2 frameshift, and 1 nonsense) in 14 unrelated individuals (confirmed de novo in 11/14) with neurodevelopmental disorders including developmental delay/intellectual disability, autism, hypotonia, and structural brain abnormalities including cerebellar vermis hypoplasia and agenesis/hypoplasia of the corpus callosum. The frameshift and nonsense variants in CDC42BPB are expected to be gene-disrupting and lead to haploinsufficiency via nonsense-mediated decay. All missense variants are located in highly conserved and functionally important protein domains/regions: 3 are found in the protein kinase domain, 2 are in the citron homology domain, and 4 in a 20-amino acid sequence between 2 coiled-coil regions, 2 of which are recurrent. Future studies will help to delineate the natural history and to elucidate the underlying biological mechanisms of the missense variants leading to the neurodevelopmental and behavioral phenotypes.

Chromatinopathies: A focus on Cornelia de Lange syndrome.

In recent years, many genes have been associated with chromatinopathies classified as "Cornelia de Lange Syndrome-like." It is known that the phenotype of these patients becomes less recognizable, overlapping to features characteristic of other syndromes caused by genetic variants affecting different regulators of chromatin structure and function. Therefore, Cornelia de Lange syndrome diagnosis might be arduous due to the seldom discordance between unexpected molecular diagnosis and clinical evaluation. Here, we review the molecular features of Cornelia de Lange syndrome, supporting the hypothesis that "CdLS-like syndromes" are part of a larger "rare disease family" sharing multiple clinical features and common disrupted molecular pathways.