Personal journeys to and in human genetics and dysmorphology.

Genetics has become a critical component of medicine over the past five to six decades. Alongside genetics, a relatively new discipline, dysmorphology, has also begun to play an important role in providing critically important diagnoses to individuals and families. Both have become indispensable to unraveling rare diseases. Almost every medical specialty relies on individuals experienced in these specialties to provide diagnoses for patients who present themselves to other doctors. Additionally, both specialties have become reliant on molecular geneticists to identify genes associated with human disorders. Many of the medical geneticists, dysmorphologists, and molecular geneticists traveled a circuitous route before arriving at the position they occupied. The purpose of collecting the memoirs contained in this article was to convey to the reader that many of the individuals who contributed to the advancement of genetics and dysmorphology since the late 1960s/early 1970s traveled along a journey based on many chances taken, replying to the necessities they faced along the way before finding full enjoyment in the practice of medical and human genetics or dysmorphology. Additionally, and of equal importance, all exhibited an ability to evolve with their field of expertise as human genetics became human genomics with the development of novel technologies.

Episignatures Stratifying Helsmoortel-Van Der Aa Syndrome Show Modest Correlation with Phenotype.

Helsmoortel-Van der Aa syndrome (HVDAS) is a neurodevelopmental condition associated with intellectual disability/developmental delay, autism spectrum disorder, and multiple medical comorbidities. HVDAS is caused by mutations in activity-dependent neuroprotective protein (ADNP). A recent study identified genome-wide DNA methylation changes in 22 individuals with HVDAS, adding to the group of neurodevelopmental disorders with an epigenetic signature. This methylation signature segregated those with HVDAS into two groups based on the location of the mutations. Here, we conducted an independent study on 24 individuals with HVDAS and replicated the existence of the two mutation-dependent episignatures. To probe whether the two distinct episignatures correlate with clinical outcomes, we used deep behavioral and neurobiological data from two prospective cohorts of individuals with a genetic diagnosis of HVDAS. We found limited phenotypic differences between the two HVDAS-affected groups and no evidence that individuals with more widespread methylation changes are more severely affected. Moreover, in spite of the methylation changes, we observed no profound alterations in the blood transcriptome of individuals with HVDAS. Our data warrant caution in harnessing methylation signatures in HVDAS as a tool for clinical stratification, at least with regard to behavioral phenotypes.

Seizures in trisomy 18: Prevalence, description, and treatment.

Changes in medical intervention over the last decade have improved outcomes for individuals with trisomy 18, the second most common human aneuploidy syndrome at birth. As children with trisomy 18 live longer, a shared concern of medical experts and parents is the occurrence and treatment of seizures. Previously published surveillance guidelines for this condition have not addressed seizure management. Using parent-reported data collected as part of the Tracking Rare Incidence Syndromes project, we report on the prevalence, course, and management of seizures in individuals with trisomy 18. Twenty-eight percent (52/186) of individuals diagnosed with trisomy 18 in our retrospective cohort experienced generalized, focal, or mixed seizures at some point in their lifetime. For many individuals, seizures were effectively managed by broad-spectrum anti-seizure medications. Correlation analysis showed that focal and generalized seizures were more likely to occur in individuals who had previously experienced infantile spasms or central apnea. Electroencephalogram testing should be considered as part of a standard screening approach in individuals with trisomy 18 to enable early diagnosis and treatment of seizures. An international registry that incorporates parent-reported and clinical data for patients with trisomy 18 may facilitate ongoing research and recruitment into clinical trials for seizure management.

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.

Reflections on observing faces in art.

The experience of art provides the visitor of a museum or gallery with the opportunity to contemplate and share the human condition both from the physical and psychological point of view. Because of the accessibility and the number of museums throughout Europe, classical European art as both sculpture and painting, affords the viewer the opportunity to experience life from one part of the world over centuries of history. These museums occasionally exhibit pieces showing a person with a human disorder and physical differences. On viewing such artwork, practitioners of health care, especially dysmorphologists, usually find themselves observing such pieces within the context of their practice. In this essay, the coauthors reflect on paintings and sculptures which remind us of our patients with similar physical and medical conditions. Various works of art also provide the opportunity to observe and view the human face from many vantage points and times in history. Several paintings are cited to illustrate the central themes of the Commentary: the human circumstance of disease and differences and the skill of observing and describing the human face.

De Novo Variants in the F-Box Protein FBXO11 in 20 Individuals with a Variable Neurodevelopmental Disorder.

Next-generation sequencing combined with international data sharing has enormously facilitated identification of new disease-associated genes and mutations. This is particularly true for genetically extremely heterogeneous entities such as neurodevelopmental disorders (NDDs). Through exome sequencing and world-wide collaborations, we identified and assembled 20 individuals with de novo variants in FBXO11. They present with mild to severe developmental delay associated with a range of features including short (4/20) or tall (2/20) stature, obesity (5/20), microcephaly (4/19) or macrocephaly (2/19), behavioral problems (17/20), seizures (5/20), cleft lip or palate or bifid uvula (3/20), and minor skeletal anomalies. FBXO11 encodes a member of the F-Box protein family, constituting a subunit of an E3-ubiquitin ligase complex. This complex is involved in ubiquitination and proteasomal degradation and thus in controlling critical biological processes by regulating protein turnover. The identified de novo aberrations comprise two large deletions, ten likely gene disrupting variants, and eight missense variants distributed throughout FBXO11. Structural modeling for missense variants located in the CASH or the Zinc-finger UBR domains suggests destabilization of the protein. This, in combination with the observed spectrum and localization of identified variants and the lack of apparent genotype-phenotype correlations, is compatible with loss of function or haploinsufficiency as an underlying mechanism. We implicate de novo missense and likely gene disrupting variants in FBXO11 in a neurodevelopmental disorder with variable intellectual disability and various other features.

The delineation of the Wolf-Hirschhorn syndrome over six decades: Illustration of the ongoing advances in phenotype analysis and cytogenomic technology.

Since Hirschhorn's description in 1961, the history and chronology of the clinical, cytogenetic, and molecular characterization of Wolf-Hirschhorn syndrome (WHS) elegantly demonstrates the remarkable advances in genetic technology over the last six decades that have paralleled the delineation of the phenotype. After mention in the Human Chromosome Newsletter of a child with a visible deletion of the top of a B chromosome group, 4-5, Hirschhorn and colleagues companioned their report with that of Wolf et al. in Humangenetik in 1965, and the condition was recognized and named. The 1960-1970s witnessed the description of many of the now classic chromosome disorders, including WHS, while HRB allowed for the recognition of chromosome syndromes with smaller deletions/duplications. FISH probes, developed in the next two decades, enabled the characterization of the critical region of WHS and improved clinical diagnosis with subtelomeric probes. Cytogenomic microarray in the early-mid 2000s led to both improved diagnosis of WHS patients and documentation of microdeletions of <5 megabases, helping to characterize the critical regions for specific component phenotypes (e.g., seizures, face). Recently exome sequencing technology has led to the discovery of WHS patients with WHSC1 loss of function variants, displaying some cardinal features of the phenotype (face, growth, and developmental delay).

Natural history study of adults with Wolf-Hirschhorn syndrome 1: Case series of personally observed 35 individuals.

Wolf-Hirschhorn syndrome (WHS) is a contiguous gene disorder, clinically delineated by prenatal and postnatal growth deficiency, distinctive craniofacial features, intellectual disability, and seizures. The disorder is caused by partial loss of material from the distal portion of the short arm of chromosome 4 (4p16.3). Although more than 300 persons with WHS have been reported in the literature, there is sparse, if any, long-term follow-up of these individuals and thus little knowledge about course and potential further complications and health risks during adulthood and advanced age. This study attempted to assess medical conditions and function of adult individuals with WHS. It was one component of a two-part investigation on adults with WHS. The other part of the study is the patient-reported outcomes study reported elsewhere. About 35 individuals with WHS (26 females; nine males), aged between 19 and 55 years were recruited. About 25 individuals were personally observed at the IRCCS Stella Maris Foundation by A.B. and followed up between 5 and 20 years; and 10 were recruited from the 4p-Support Group, The United States. Of note, 23/35 (66%) are close to total care. About 11 out of 35 (31%) were partly self-independent, requiring supervision on certain daily routines, and 1 out of 35 (3%) was fully independent. However, a positive perspective is given by the overall good health enjoyed by the 66% of our cohort of individuals. Overall, quality of life and level of function into adulthood appear to be less critical than anticipated from previous studies.

Natural history study of adults with Wolf-Hirschhorn syndrome 2: Patient-reported outcomes study.

Wolf-Hirschhorn syndrome (WHS) is a contiguous gene disorder consisting of prenatal and postnatal growth deficiency, distinctive craniofacial features, intellectual disability, and seizures. The condition is caused by a partial loss of material from the distal portion of the short arm of chromosome 4 (4p16.3). While there are many reports of individuals with WHS, useful data on long-term survival and life status of adults with the syndrome are very limited. There are only 11 reports of individuals over the age of 18 years in the literature. Establishing the medical manifestations of adults with WHS would be helpful in establishing appropriate health supervision guidelines. This study was one component of a two-part investigation on adults with WHS. This patient-reported outcomes study (PROS) was accomplished by using the registry of rare diseases at Sanford Research, Coordination of Rare Diseases (CoRDS)at Sanford. Thirty family members or caretakers of 30 adults with WHS/4p- entered into the CoRDS registry and completed some or all of the survey data. Twelve caretakers completed the recently-added survey on activities of daily living. Two of the individuals with WHS were partly independent while 10 required total care. The results provide novel information on daily life and independence in adults with WHS. Importantly, the majority of caretakers reported that the adults were in good health. The data from both parts of the study will contribute to our knowledge of the natural history of the syndrome and guide in establishing appropriate health supervision guidelines for adults with WHS.

International meeting on Wolf-Hirschhorn syndrome: Update on the nosology and new insights on the pathogenic mechanisms for seizures and growth delay.

"An International Meeting on Wolf-Hirschhorn Syndrome (WHS)" was held at The University Hospital La Paz in Madrid, Spain (October 13-14, 2017). One hundred and twenty-five people, including physicians, scientists and affected families, attended the meeting. Parent and patient advocates from the Spanish Association of WHS opened the meeting with a panel discussion to set the stage regarding their hopes and expectations for therapeutic advances. In keeping with the theme on therapeutic development, the sessions followed a progression from description of the phenotype and definition of therapeutic endpoints, to definition of genomic changes. These proceedings will review the major points of discussion.

Delineation of MidXq28-duplication syndrome distal to MECP2 and proximal to RAB39B genes.

Two distinct genomic disorders have been linked to Xq28-gains, namely Xq28-duplications including MECP2 and Int22h1/Int22h2-mediated duplications involving RAB39B. Here, we describe six unrelated patients, five males and one female, with Xq28-gains distal to MECP2 and proximal to the Int22h1/Int22h2 low copy repeats. Comparison with patients carrying overlapping duplications in the literature defined the MidXq28-duplication syndrome featuring intellectual disability, language impairment, structural brain malformations, microcephaly, seizures and minor craniofacial features. The duplications overlapped for 108 kb including FLNA, RPL10 and GDI1 genes, highly expressed in brain and candidates for the neurologic phenotype.

Perinatal distress in 1p36 deletion syndrome can mimic hypoxic ischemic encephalopathy.

1p36 deletion syndrome is a well-described condition with a recognizable phenotype, including cognitive impairment, seizures, and structural brain anomalies such as periventricular leukomalacia (PVL). In a large series of these individuals by Battaglia et al., "birth history was notable in 50% of the cases for varying degrees of perinatal distress." Given the potential for perinatal distress, seizures and PVL, we questioned if this disorder has clinical overlap with hypoxic ischemic encephalopathy (HIE). We reviewed the medical records of 69 individuals with 1p36 deletion to clarify the perinatal phenotype of this disorder and determine if there is evidence of perinatal distress and/or hypoxic injury. Our data provides evidence that these babies have signs of perinatal distress. The majority (59% term; 75% preterm) needed resuscitation and approximately 18% had cardiac arrest. Most had abnormal brain imaging (84% term; 73% preterm) with abnormal white matter findings in over half of patients. PVL or suggestion of "hypoxic insult" was present in 18% of term and 45% of preterm patients. In conclusion, individuals with 1p36 deletion have evidence of perinatal distress, white matter changes, and seizures, which can mimic HIE but are likely related to their underlying chromosome disorder.

Risk of hepatic neoplasms in Wolf-Hirschhorn syndrome (4p-): Four new cases and review of the literature.

Wolf-Hirschhorn syndrome (WHS) is a rare contiguous gene deletion disorder characterized by distinctive craniofacial features, prenatal/postnatal growth deficiency, intellectual disability, and seizures. Various malformations of internal organs are also seen. Neoplasia has not been documented as a typical feature of WHS. We review the three prior reports of hepatic neoplasia in WHS and add four previously unreported individuals. We propose that, in the context of the rarity of WHS, these seven cases suggest that hepatocellular neoplasia may be a feature of WHS.

A survey of antiepileptic drug responses identifies drugs with potential efficacy for seizure control in Wolf-Hirschhorn syndrome.

Seizures are present in over 90% of infants and children with Wolf-Hirschhorn syndrome (WHS). When present, they significantly affect quality of life. The goal of this study was to use caregiver reports to describe the comparative efficacies of commonly used antiepileptic medications in a large population of individuals with WHS. A web-based, confidential caregiver survey was developed to capture seizure semiology and a chronologic record of seizure treatments as well as responses to each treatment. Adverse events for each drug were also cataloged. We received 141 complete survey responses (47% response rate) describing the seizures of individuals ranging in age from 4months to 61years (90 females: 51 males). Using the Early Childhood Epilepsy Severity Scale (E-Chess), WHS-associated seizures are demonstrably severe regardless of deletion size. The best-performing antiepileptic drugs (AEDs) for controlling seizures in this cohort were broad spectrum drugs clobazam, levetiracetam, and lamotrigine; whereas, the three commonly used carboxamide class drugs: carbamazepine, phenytoin, and oxcarbazepine, were reported to have little effect on, or even exacerbate, seizures. The carboxamide class drugs, along with phenobarbital and topiramate, were also associated with the highest rate of intolerance due to cooccurrence of adverse events. Levetiracetam, clobazam, and clonazepam demonstrated higher tolerability and comparatively less severe adverse events (Wilcoxon rank sum comparison between performance of levetiracetam and carboxamide class drugs gives a p<0.0001 after multiple comparison adjustment). This is the largest survey to date assessing WHS seizures. This study design is susceptible to possible bias, as the data are largely drawn from caregiver report and investigators had limited access to medical records. Despite this, our data suggest that the genetic etiology of seizures, together with an accurate electroclinical delineation, are important components of drug selection, even in contiguous gene syndromes which may have complex seizure etiologies.

Mutations in CKAP2L, the human homolog of the mouse Radmis gene, cause Filippi syndrome.

Filippi syndrome is a rare, presumably autosomal-recessive disorder characterized by microcephaly, pre- and postnatal growth failure, syndactyly, and distinctive facial features, including a broad nasal bridge and underdeveloped alae nasi. Some affected individuals have intellectual disability, seizures, undescended testicles in males, and teeth and hair abnormalities. We performed homozygosity mapping and whole-exome sequencing in a Sardinian family with two affected children and identified a homozygous frameshift mutation, c.571dupA (p.Ile191Asnfs(∗)6), in CKAP2L, encoding the protein cytoskeleton-associated protein 2-like (CKAP2L). The function of this protein was unknown until it was rediscovered in mice as Radmis (radial fiber and mitotic spindle) and shown to play a pivotal role in cell division of neural progenitors. Sanger sequencing of CKAP2L in a further eight unrelated individuals with clinical features consistent with Filippi syndrome revealed biallelic mutations in four subjects. In contrast to wild-type lymphoblastoid cell lines (LCLs), dividing LCLs established from the individuals homozygous for the c.571dupA mutation did not show CKAP2L at the spindle poles. Furthermore, in cells from the affected individuals, we observed an increase in the number of disorganized spindle microtubules owing to multipolar configurations and defects in chromosome segregation. The observed cellular phenotypes are in keeping with data from in vitro and in vivo knockdown studies performed in human cells and mice, respectively. Our findings show that loss-of-function mutations in CKAP2L are a major cause of Filippi syndrome.

Chromosomal microarray testing identifies a 4p terminal region associated with seizures in Wolf-Hirschhorn syndrome.

BACKGROUND: Wolf-Hirschhorn syndrome (WHS) is a contiguous gene deletion syndrome involving variable size deletions of the 4p16.3 region. Seizures are frequently, but not always, associated with WHS. We hypothesised that the size and location of the deleted region may correlate with seizure presentation. METHODS: Using chromosomal microarray analysis, we finely mapped the breakpoints of copy number variants (CNVs) in 48 individuals with WHS. Seizure phenotype data were collected through parent-reported answers to a comprehensive questionnaire and supplemented with available medical records. RESULTS: We observed a significant correlation between the presence of an interstitial 4p deletion and lack of a seizure phenotype (Fisher's exact test p=3.59e-6). In our cohort, there were five individuals with interstitial deletions with a distal breakpoint at least 751 kbp proximal to the 4p terminus. Four of these individuals have never had an observable seizure, and the fifth individual had a single febrile seizure at the age of 1.5 years. All other individuals in our cohort whose deletions encompass the terminal 751 kbp region report having seizures typical of WHS. Additional examples from the literature corroborate these observations and further refine the candidate seizure susceptibility region to a region 197 kbp in size, starting 368 kbp from the terminus of chromosome 4. CONCLUSIONS: We identify a small terminal region of chromosome 4p that represents a seizure susceptibility region. Deletion of this region in the context of WHS is sufficient for seizure occurrence.

Deletions and de novo mutations of SOX11 are associated with a neurodevelopmental disorder with features of Coffin-Siris syndrome.

BACKGROUND: SOX11 is a transcription factor proposed to play a role in brain development. The relevance of SOX11 to human developmental disorders was suggested by a recent report of SOX11 mutations in two patients with Coffin-Siris syndrome. Here we further investigate the role of SOX11 variants in neurodevelopmental disorders. METHODS: We used array based comparative genomic hybridisation and trio exome sequencing to identify children with intellectual disability who have deletions or de novo point mutations disrupting SOX11. The pathogenicity of the SOX11 mutations was assessed using an in vitro gene expression reporter system. Loss-of-function experiments were performed in xenopus by knockdown of Sox11 expression. RESULTS: We identified seven individuals with chromosome 2p25 deletions involving SOX11. Trio exome sequencing identified three de novo SOX11 variants, two missense (p.K50N; p.P120H) and one nonsense (p.C29*). The biological consequences of the missense mutations were assessed using an in vitro gene expression system. These individuals had microcephaly, developmental delay and shared dysmorphic features compatible with mild Coffin-Siris syndrome. To further investigate the function of SOX11, we knocked down the orthologous gene in xenopus. Morphants had significant reduction in head size compared with controls. This suggests that SOX11 loss of function can be associated with microcephaly. CONCLUSIONS: We thus propose that SOX11 deletion or mutation can present with a Coffin-Siris phenotype.

Spectrum of epilepsy and electroencephalogram patterns in idic (15) syndrome.

Previous reports summarized the seizure types occurring in patients with idic(15) syndrome. To better define this issue, we retrospectively analyzed the evolution of electroencephalogram findings and seizures in 35 patients with confirmed idic(15). Epilepsy occurred in 28 patients (80%), with a median age of onset of 3 years 3 months. The initial seizures were infantile spasms associated with a hypsarrhythmic electroencephalogram (nine patients), focal/generalized tonic (seven patients), or atypical absences (eight patients). High doses of oral steroids were given in all nine children with infantile spasms, with remission of seizures and resolution of electroencephalogram abnormalities. Among them, three were seizure free at the time of evaluation, but six later developed Lennox-Gastaut syndrome or Lennox-Gastaut-like syndrome. The eight patients with atypical absences developed Lennox-Gastaut syndrome or Lennox-Gastaut-like syndrome. Epilepsy was well controlled in 32% of the patients; satisfactorily controlled (seizures reduced >75%) in 21.4%; partially controlled (seizures reduced <50%) in 10.7%; and uncontrolled in 32%. One patient was not taking any anti-epileptic drugs by his parents' choice. Fourteen percent were on monotherapy; whereas the other 82% were on polytherapy. Seizures stopped at a median age of 5 years 5 months. The interictal electroencephalogram showed slow/sharp waves, and/or biphasic spikes-polyspikes, spike/wave complexes, and an excess of fast activity mainly over the fronto-temporal areas. Epilepsy is a major clinical challenge in patients with idic(15), associated with a poor prognosis in 55%. Frontal lobe seizures are a novel finding. © 2016 Wiley Periodicals, Inc.

Functional impact of global rare copy number variation in autism spectrum disorders.

The autism spectrum disorders (ASDs) are a group of conditions characterized by impairments in reciprocal social interaction and communication, and the presence of restricted and repetitive behaviours. Individuals with an ASD vary greatly in cognitive development, which can range from above average to intellectual disability. Although ASDs are known to be highly heritable ( approximately 90%), the underlying genetic determinants are still largely unknown. Here we analysed the genome-wide characteristics of rare (<1% frequency) copy number variation in ASD using dense genotyping arrays. When comparing 996 ASD individuals of European ancestry to 1,287 matched controls, cases were found to carry a higher global burden of rare, genic copy number variants (CNVs) (1.19 fold, P = 0.012), especially so for loci previously implicated in either ASD and/or intellectual disability (1.69 fold, P = 3.4 x 10(-4)). Among the CNVs there were numerous de novo and inherited events, sometimes in combination in a given family, implicating many novel ASD genes such as SHANK2, SYNGAP1, DLGAP2 and the X-linked DDX53-PTCHD1 locus. We also discovered an enrichment of CNVs disrupting functional gene sets involved in cellular proliferation, projection and motility, and GTPase/Ras signalling. Our results reveal many new genetic and functional targets in ASD that may lead to final connected pathways.

Wolf-Hirschhorn syndrome: A review and update.

Since 4p- was first described in 1961, significant progress has been made in our understanding of this classic deletion disorder. We have been able to establish a more complete picture of the WHS phenotype associated with distal 4p monosomy, and we are working to delineate the phenotypic effects when each gene on distal 4p is hemizygous. Our aim is to provide genotype-specific anticipatory guidance and recommendations to families of individuals with a diagnosis of WHS. In addition, establishing the molecular underpinnings of the disorder will potentially suggest targets for molecular treatments. Thus, the next step is to determine the precise effects of specific gene deletions. As we look forward to deepening our understanding of distal 4p deletion, our focus will continue to be on the establishment of robust genotype-phenotype correlations and the penetrance of these phenotypes. We will continue to follow our WHS cohort closely as they age to determine the presence or absence of some of these comorbidities, including hepatic neoplasms, hematopoietic dysfunction, and recurrence of seizures. We will also continue to refine the critical regions for other phenotypes as we enroll additional (hopefully informative) participants into the research study and as the mechanisms of the genes in these regions are elucidated. New animal models will also be developed to further our understanding of the effects of hemizygosity as well as to serve as models for treatment development.