Open reduction internal fixation with bone grafting for scapular body nonunion: A case report

Scapular body fractures are rare fractures that represent less than 1 % of all fractures and are typically associated with a high energy mechanism of injury. Traditionally these fractures have been treated non-operatively, resulting in union of the fracture and acceptable patient outcomes. We present a case of symptomatic scapular body fracture nonunion following non-operative management that was treated with open reduction and internal fixation with local autologous bone grafting. Our patient went on to successful union of his fracture as well as drastic improvement in shoulder function, range of motion, strength, and patient reported outcome measures assessed throughout his treatment course. The authors believe that scapular body fracture nonunion should be of clinical suspicion in forming the differential diagnosis for a patient who had previously sustained a scapular body fracture with persistent pain and failure to improve following non-operative management. We believe that open reduction and internal fixation with bone grafting can help promote fracture union in these patients and may result in improved shoulder function post-operatively.

Deletion of conserved non-coding sequences downstream from NKX2-1: A novel disease-causing mechanism for benign hereditary chorea

Background

Benign hereditary chorea (BHC) is an autosomal dominant disorder characterized by early‐onset non‐progressive involuntary movements. Although NKX2‐1 mutations or deletions are the cause of BHC, some BHC families do not have pathogenic alterations in the NKX2‐1 gene, indicating that mutations of non‐coding regulatory elements of NKX2‐1 may also play a role.

Methods and Results

By using whole‐genome microarray analysis, we identified a 117 Kb founder deletion in three apparently unrelated BHC families that were negative for NKX2‐1 sequence variants. Targeted next generation sequencing analysis confirmed the deletion and showed that it was part of a complex local genomic rearrangement. In addition, we also detected a 648 Kb de novo deletion in an isolated BHC case. Both deletions are located downstream from NKX2‐1 on chromosome 14q13.2‐q13.3 and share a 33 Kb smallest region of overlap with six previously reported cases. This region has no gene but contains multiple evolutionarily highly conserved non‐coding sequences.

Conclusion

We propose that the deletion of potential regulatory elements necessary for NKX2‐1 expression in this critical region is responsible for BHC phenotype in these patients, and this is a novel disease‐causing mechanism for BHC.

Disruption of PHF21A causes syndromic intellectual disability with craniofacial anomalies, epilepsy, hypotonia, and neurobehavioral problems including autism

Background

PHF21A has been associated with intellectual disability and craniofacial anomalies based on its deletion in the Potocki-Shaffer syndrome region at 11p11.2 and its disruption in three patients with balanced translocations. In addition, three patients with de novo truncating mutations in PHF21A were reported recently. Here, we analyze genomic data from seven unrelated individuals with mutations in PHF21A and provide detailed clinical descriptions, further expanding the phenotype associated with PHF21A haploinsufficiency.

Methods

Diagnostic trio whole exome sequencing, Sanger sequencing, use of GeneMatcher, targeted gene panel sequencing, and MiSeq sequencing techniques were used to identify and confirm variants. RT-qPCR was used to measure the normal expression pattern of PHF21A in multiple human tissues including 13 different brain tissues. Protein-DNA modeling was performed to substantiate the pathogenicity of the missense mutation.

Results

We have identified seven heterozygous coding mutations, among which six are de novo (not maternal in one). Mutations include four frameshifts, one nonsense mutation in two patients, and one heterozygous missense mutation in the AT Hook domain, predicted to be deleterious and likely to cause loss of PHF21A function. We also found a new C-terminal domain composed of an intrinsically disordered region. This domain is truncated in six patients and thus likely to play an important role in the function of PHF21A, suggesting that haploinsufficiency is the likely underlying mechanism in the phenotype of seven patients. Our results extend the phenotypic spectrum of PHF21A mutations by adding autism spectrum disorder, epilepsy, hypotonia, and neurobehavioral problems. Furthermore, PHF21A is highly expressed in the human fetal brain, which is consistent with the neurodevelopmental phenotype.

Conclusion

Deleterious nonsense, frameshift, and missense mutations disrupting the AT Hook domain and/or an intrinsically disordered region in PHF21A were found to be associated with autism spectrum disorder, epilepsy, hypotonia, neurobehavioral problems, tapering fingers, clinodactyly, and syndactyly, in addition to intellectual disability and craniofacial anomalies. This suggests that PHF21A is involved in autism spectrum disorder and intellectual disability, and its haploinsufficiency causes a diverse neurological phenotype.

Electronic supplementary material

The online version of this article (10.1186/s13229-019-0286-0) contains supplementary material, which is available to authorized users.

Clinical exome sequencing reveals locus heterogeneity and phenotypic variability of cohesinopathies

PURPOSE

Defects in the cohesin pathway are associated with cohesinopathies, notably Cornelia de Lange syndrome (CdLS). We aimed to delineate pathogenic variants in known and candidate cohesinopathy genes from a clinical exome perspective.

METHODS

We retrospectively studied patients referred for clinical exome sequencing (CES, N = 10,698). Patients with causative variants in novel or recently described cohesinopathy genes were enrolled for phenotypic characterization.

RESULTS

Pathogenic or likely pathogenic single-nucleotide and insertion/deletion variants (SNVs/indels) were identified in established disease genes including NIPBL (N = 5), SMC1A (N = 14), SMC3 (N = 4), RAD21 (N = 2), and HDAC8 (N = 8). The phenotypes in this genetically defined cohort skew towards the mild end of CdLS spectrum as compared with phenotype-driven cohorts. Candidate or recently reported cohesinopathy genes were supported by de novo SNVs/indels in STAG1 (N = 3), STAG2 (N = 5), PDS5A (N = 1), and WAPL (N = 1), and one inherited SNV in PDS5A. We also identified copy-number deletions affecting STAG1 (two de novo, one of unknown inheritance) and STAG2 (one of unknown inheritance). Patients with STAG1 and STAG2 variants presented with overlapping features yet without characteristic facial features of CdLS.

CONCLUSION

CES effectively identified disease-causing alleles at the mild end of the cohensinopathy spectrum and enabled characterization of candidate disease genes.

Tuberculosis in Canada: 2017

BACKGROUND

Tuberculosis (TB) is a major global health problem that affected an estimated 10 million people worldwide in 2017. The Public Health Agency of Canada monitors active TB disease through a national surveillance system, which is a collaborative effort with the provinces and territories.

OBJECTIVE

To present an epidemiological summary of active TB cases reported in 2017. Results are discussed in the context of the previous year's data. Treatment outcomes for cases diagnosed in 2016 are also presented.

METHODS

The Canadian Tuberculosis Reporting System is a case-based surveillance system that maintains non-nominal data on people diagnosed with active TB disease in Canada. Data are collected annually from the provinces and territories, analyzed by the Public Health Agency of Canada and validated by each province and territory.

RESULTS

There were 1,796 cases of active TB reported in Canada in 2017 compared with 1,750 cases in 2016, representing a 2.6% increase. There was a corresponding increase in the incidence rate from 4.8 to 4.9 per 100,000 population. Foreign born individuals continued to make up the majority of cases (71.8%) and the incidence rate remained highest among Canadian born Indigenous people (21.5 per 100,000 population), in particular, among the Inuit population (205.8 per 100,000 population). Consistent with the previous decade, TB incidence rates in 2017 continued to be higher among males (5.5 per 100,000) compared with females (4.3 per 100,000), and the majority of cases (45.6%) were between the ages of 15 and 44 years. The incidence rate was highest among adults over 75 years of age (13.8 cases per 100,000 for males and 7.2 for females). Of the TB cases diagnosed in 2016 where outcomes were reported, 80.4% were treated successfully.

CONCLUSION

Although the incidence rate of TB in Canada in 2017 remained low in the global context and has been relatively stable over the last decade, both the case count and rate have been gradually increasing since 2014. Indigenous and foreign born Canadians continued to be disproportionately represented among TB cases. Canadian TB surveillance data are an important source of information for monitoring progress and informing public health action related to reducing the burden of TB in Canada, with the ultimate goal of TB elimination.

The ARID1B spectrum in 143 patients: from nonsyndromic intellectual disability to Coffin-Siris syndrome

Purpose

Pathogenic variants in ARID1B are one of the most frequent causes of intellectual disability (ID) as determined by large-scale exome sequencing studies. Most studies published thus far describe clinically diagnosed Coffin–Siris patients (ARID1B-CSS) and it is unclear whether these data are representative for patients identified through sequencing of unbiased ID cohorts (ARID1B-ID). We therefore sought to determine genotypic and phenotypic differences between ARID1B-ID and ARID1B-CSS. In parallel, we investigated the effect of different methods of phenotype reporting.

Methods

Clinicians entered clinical data in an extensive web-based survey.

Results

79 ARID1B-CSS and 64 ARID1B-ID patients were included. CSS-associated dysmorphic features, such as thick eyebrows, long eyelashes, thick alae nasi, long and/or broad philtrum, small nails and small or absent fifth distal phalanx and hypertrichosis, were observed significantly more often (p < 0.001) in ARID1B-CSS patients. No other significant differences were identified.

Conclusion

There are only minor differences between ARID1B-ID and ARID1B-CSS patients. ARID1B-related disorders seem to consist of a spectrum, and patients should be managed similarly. We demonstrated that data collection methods without an explicit option to report the absence of a feature (such as most Human Phenotype Ontology-based methods) tended to underestimate gene-related features.

Kaufman oculocerebrofacial syndrome: Novel UBE3B mutations and clinical features in four unrelated patients

The "blepharophimosis-mental retardation" syndromes (BMRS) consist of a group of clinically and genetically heterogeneous congenital malformation syndromes, where short palpebral fissures and intellectual disability associate with a distinct set of other morphological features. Kaufman oculocerebrofacial syndrome represents a rare and recently reevaluated entity within the BMR syndromes and is caused by biallelic mutations of UBE3B. Affected individuals typically show microcephaly, impaired somatic growth, gastrointestinal and genitourinary problems, ectodermal anomalies and a characteristic face with short, upslanted palpebral fissures, depressed nasal bridge. and anteverted nares. Here we present four patients with five novel UBE3B mutations and propose the inclusion of clinical features to the characteristics of Kaufman oculocerebrofacial syndrome, including prominence of the cheeks and limb anomalies.

Phenotypic and molecular characterisation of CDK13-related congenital heart defects, dysmorphic facial features and intellectual developmental disorders

Background

De novo missense variants in CDK13 have been described as the cause of syndromic congenital heart defects in seven individuals ascertained from a large congenital cardiovascular malformations cohort. We aimed to further define the phenotypic and molecular spectrum of this newly described disorder.

Methods

To minimise ascertainment bias, we recruited nine additional individuals with CDK13 pathogenic variants from clinical and research exome laboratory sequencing cohorts. Each individual underwent dysmorphology exam and comprehensive medical history review.

Results

We demonstrate greater than expected phenotypic heterogeneity, including 33% (3/9) of individuals without structural heart disease on echocardiogram. There was a high penetrance for a unique constellation of facial dysmorphism and global developmental delay, as well as less frequently seen renal and sacral anomalies. Two individuals had novel CDK13 variants (p.Asn842Asp, p.Lys734Glu), while the remaining seven unrelated individuals had a recurrent, previously published p.Asn842Ser variant. Summary of all variants published to date demonstrates apparent restriction of pathogenic variants to the protein kinase domain with clustering in the ATP and magnesium binding sites.

Conclusions

Here we provide detailed phenotypic and molecular characterisation of individuals with pathogenic variants in CDK13 and propose management guidelines based upon the estimated prevalence of anomalies identified.

Electronic supplementary material

The online version of this article (doi:10.1186/s13073-017-0463-8) contains supplementary material, which is available to authorized users.

Tinzaparin thromboprophylaxis prescribing practice after caesarean delivery 2009-2014

BACKGROUND

National guidelines have been developed to ensure correct dosing of tinzaparin for women delivered by caesarean delivery (CD) to reduce the risk of venous thromboembolism.

AIMS

The aim of this study is to examine the impact of implementation of national guidelines on thromboprophylaxis prescribing practice for women undergoing CD in a university maternity hospital.

METHODS

Details of tinzaparin usage were obtained from the Hospital pharmacy for the years 2009-2014. Information on CD and pulmonary embolism (PE) were obtained from the Hospital's annual clinical reports.

RESULTS

Following guideline recommendations on weight-based tinzaparin for all women undergoing CD, the usage of syringes prefilled with tinzaparin 4500 IU increased from 526 to 8502 (P < 0.001) and usage of syringes prefilled with tinzaparin 10,000 IU increased from 36 to 910 (P < 0.001). Usage of syringes prefilled with tinzaparin 3500 IU decreased from 8216 in 2009 to 39 in 2014 (P < 0.001). During 2008-2010, there were two cases of PE after CD, both of whom received an inadequate dose of prophylactic tinzaparin. During 2011-2014 there were no cases of PE diagnosed after a total of 9427 CDs.

CONCLUSIONS

The development of national guidelines on thromboprophylaxis after CD was followed by a significant change in weight-based prescribing of tinzaparin. Following implementation, there have been no cases of PE after CD.

Tuberculosis in Canada - Summary 2015

BACKGROUND

Tuberculosis (TB) is a global health problem that affects an estimated 10 million people each year. In Canada, the Public Health Agency of Canada (PHAC) monitors active TB disease through the Canadian Tuberculosis Reporting System (CTBRS).

OBJECTIVE

To report on and analyze the number of new and re-treatment cases of TB cases in Canada reported for 2015. Results are discussed in the context of previous year's data. Treatment outcomes for cases diagnosed in 2014 are also presented.

METHODS

The CTBRS is a case-based surveillance system that maintains non-nominal data on active cases of TB. Data are collected and analyzed by PHAC and validated by each province and territory; no statistical tests were used.

RESULTS

A total of 1,639 cases of active TB disease were reported in 2015, representing a slight increase from the number of cases reported in 2014 (1,614) and a corresponding increase in the incidence rate from 4.5 per 100,000 to 4.6 per 100,000 population. Although the incidence rate of TB remained highest in Nunavut at 119.2 per 100,000 population in 2015, it was nearly half of what it was in 2014. An outbreak in Newfoundland and Labrador resulted in a notable increase in the number of reported cases and incidence rate in this province. In 2015, males accounted for just over half of the reported cases at 53% and older Canadians carried the highest burden of TB with an incidence rate of 10.3 per 100,000 population. Foreign-born individuals continued to account for the majority of reported cases at 71%, but the incidence rate remained highest among Canadian-born Indigenous people at 17.1 per 100,000 population and in particular within the Inuit population at 166.2 per 100,000. Pulmonary TB remained the most commonly reported site of disease. Treatment outcome data for cases reported in 2014 indicated that 85% of cases had been cured or had completed treatment.

CONCLUSION

Tuberculosis rates in Canada have changed little over the last decade and overall, remain stable and low in the global context. However, foreign-born individuals and Indigenous Canadians continued to be disproportionately represented among reported cases of TB in 2015. As the primary source of national data on TB cases, the data within this report provide timely information for public health action, as well as policy and program development and assessment.

GRIN1 mutation associated with intellectual disability alters NMDA receptor trafficking and function

N-methyl-d-aspartate receptors (NMDARs) play important roles in brain development and neurological disease. We report two individuals with similar dominant de novo GRIN1 mutations (c.1858 G>A and c.1858 G>C; both p.G620R). Both individuals presented at birth with developmental delay and hypotonia associated with behavioral abnormalities and stereotypical movements. Recombinant NMDARs containing the mutant GluN1-G620R together with either GluN2A or GluN2B were evaluated for changes in their trafficking to the plasma membrane and their electrophysiological properties. GluN1-G620R/GluN2A complexes showed a mild reduction in trafficking, a ~2-fold decrease in glutamate and glycine potency, a strong decrease in sensitivity to Mg²⁺ block, and a significant reduction of current responses to a maximal effective concentration of agonists. GluN1-G620R/GluN2B complexes showed significantly reduced delivery of protein to the cell surface associated with similarly altered electrophysiology. These results indicate these individuals may have suffered neurodevelopmental deficits as a result of the decreased presence of GluN1-G620R/GluN2B complexes on the neuronal surface during embryonic brain development and reduced current responses of GluN1-G620R-containing NMDARs after birth. These cases emphasize the importance of comprehensive functional characterization of de novo mutations and illustrates how a combination of several distinct features of NMDAR expression, trafficking and function can be present and influence phenotype.

Identification of novel toluene monooxygenase genes in a hydrocarbon-polluted sediment using sequence- and function-based screening of metagenomic libraries

The microbial potential for toluene degradation within sediments from a tar oil-contaminated site in Flingern, Germany, was assessed using a metagenomic approach. High molecular weight environmental DNA from contaminated sediments was extracted, purified, and cloned into fosmid and BAC vectors and transformed into Escherichia coli. The fosmid library was screened by hybridization with a PCR amplicon of the α-subunit of the toluene 4-monooxygenase gene to identify genes and pathways encoding toluene degradation. Fourteen clones were recovered from the fosmid library, among which 13 were highly divergent from known tmoA genes and several had the closest relatives among Acinetobacter species. The BAC library was transferred to the heterologous hosts Cupriavidus metallidurans (phylum Proteobacteria) and Edaphobacter aggregans (phylum Acidobacteria). The resulting libraries were screened for expression of toluene degradation in the non-degradative hosts. From expression in C. metallidurans, three novel toluene monooxygenase-encoding operons were identified that were located on IncP1 plasmids. The E. aggregans-hosted BAC library led to the isolation of a cloned genetic locus putatively derived from an Acidobacteria taxon that contained genes involved in aerobic and anaerobic toluene degradation. These data suggest the important role of plasmids in the spread of toluene degradative capacity and indicate putative novel tmoA genes present in this hydrocarbon-polluted environment.

De Novo Truncating Variants in SON Cause Intellectual Disability, Congenital Malformations, and Failure to Thrive

SON is a key component of the spliceosomal complex and a critical mediator of constitutive and alternative splicing. Additionally, SON has been shown to influence cell-cycle progression, genomic integrity, and maintenance of pluripotency in stem cell populations. The clear functional relevance of SON in coordinating essential cellular processes and its presence in diverse human tissues suggests that intact SON might be crucial for normal growth and development. However, the phenotypic effects of deleterious germline variants in SON have not been clearly defined. Herein, we describe seven unrelated individuals with de novo variants in SON and propose that deleterious variants in SON are associated with a severe multisystem disorder characterized by developmental delay, persistent feeding difficulties, and congenital malformations, including brain anomalies.

Hypoxia-upregulated microRNA-630 targets Dicer, leading to increased tumor progression

MicroRNAs (miRNAs) are small RNA molecules that affect cellular processes by controlling gene expression. Recent studies have shown that hypoxia downregulates Drosha and Dicer, key enzymes in miRNA biogenesis, causing a decreased pool of miRNAs in cancer and resulting in increased tumor growth and metastasis. Here we demonstrate a previously unrecognized mechanism by which hypoxia downregulates Dicer. We found that miR-630, which is upregulated under hypoxic conditions, targets and downregulates Dicer expression. In an orthotopic mouse model of ovarian cancer, delivery of miR-630 using 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) nanoliposomes resulted in increased tumor growth and metastasis, and decreased Dicer expression. Treatment with the combination of anti-miR-630 and anti-vascular endothelial growth factor antibody in mice resulted in rescue of Dicer expression and significantly decreased tumor growth and metastasis. These results indicate that targeting miR-630 is a promising approach to overcome Dicer deregulation in cancer. As demonstrated in the study, use of DOPC nanoliposomes for anti-miR delivery serves as a better alternative approach to cell line-based overexpression of sense or antisense miRNAs, while avoiding potential in vitro selection effects. Findings from this study provide a new understanding of miRNA biogenesis downregulation observed under hypoxia and suggest therapeutic avenues to target this dysregulation in cancer.

Respiratory motile cilia dysfunction in a patient with cranioectodermal dysplasia

Ciliopathies such as cranioectodermal dysplasia, Sensenbrenner syndrome, short-rib polydactyly, and Jeune syndrome are associated with respiratory complications arising from rib cage dysplasia. While such ciliopathies have been demonstrated to involve primary cilia defects, we show motile cilia dysfunction in the airway of a patient diagnosed with cranioectodermal dysplasia. While this patient had mild thoracic dystrophy not requiring surgical treatment, there was nevertheless newborn respiratory distress, restrictive airway disease with possible obstructive airway involvement, repeated respiratory infections, and atelectasis. High-resolution videomicroscopy of nasal epithelial biopsy showed immotile/dyskinetic cilia and nasal nitric oxide was reduced, both of which are characteristics of primary ciliary dyskinesia, a sinopulmonary disease associated with mucociliary clearance defects due to motile cilia dysfunction in the airway. Exome sequencing analysis of this patient identified compound heterozygous mutations in WDR35, but no mutations in any of the 30 known primary ciliary dyskinesia genes or other cilia-related genes. Given that WDR35 is only known to be required for primary cilia function, we carried out WDR35 siRNA knockdown in human respiratory epithelia to assess the role of WDR35 in motile cilia function. This showed WDR35 deficiency disrupted ciliogenesis in the airway, indicating WDR35 is also required for formation of motile cilia. Together, these findings suggest patients with WDR35 mutations have an airway mucociliary clearance defect masked by their restrictive airway disease.

Mutations in PURA cause profound neonatal hypotonia, seizures, and encephalopathy in 5q31.3 microdeletion syndrome

5q31.3 microdeletion syndrome is characterized by neonatal hypotonia, encephalopathy with or without epilepsy, and severe developmental delay, and the minimal critical deletion interval harbors three genes. We describe 11 individuals with clinical features of 5q31.3 microdeletion syndrome and de novo mutations in PURA, encoding transcriptional activator protein Pur-α, within the critical region. These data implicate causative PURA mutations responsible for the severe neurological phenotypes observed in this syndrome.

Lithium pellet production (LiPP): a device for the production of small spheres of lithium

With lithium as a fusion material gaining popularity, a method for producing lithium pellets relatively quickly has been developed for NSTX. The Lithium Pellet Production device is based on an injector with a sub-millimeter diameter orifice and relies on a jet of liquid lithium breaking apart into small spheres via the Plateau-Rayleigh instability. A prototype device is presented in this paper and for a pressure difference of ΔP = 5 Torr, spheres with diameters between 0.91 < D < 1.37 mm have been produced with an average diameter of D = 1.14 mm, which agrees with the developed theory. Successive tests performed at Princeton Plasma Physics Laboratory with Wood's metal have confirmed the dependence of sphere diameter on pressure difference as predicted.

Phenotypic heterogeneity of genomic disorders and rare copy-number variants

BACKGROUND

Some copy-number variants are associated with genomic disorders with extreme phenotypic heterogeneity. The cause of this variation is unknown, which presents challenges in genetic diagnosis, counseling, and management.

METHODS

We analyzed the genomes of 2312 children known to carry a copy-number variant associated with intellectual disability and congenital abnormalities, using array comparative genomic hybridization.

RESULTS

Among the affected children, 10.1% carried a second large copy-number variant in addition to the primary genetic lesion. We identified seven genomic disorders, each defined by a specific copy-number variant, in which the affected children were more likely to carry multiple copy-number variants than were controls. We found that syndromic disorders could be distinguished from those with extreme phenotypic heterogeneity on the basis of the total number of copy-number variants and whether the variants are inherited or de novo. Children who carried two large copy-number variants of unknown clinical significance were eight times as likely to have developmental delay as were controls (odds ratio, 8.16; 95% confidence interval, 5.33 to 13.07; P=2.11×10(-38)). Among affected children, inherited copy-number variants tended to co-occur with a second-site large copy-number variant (Spearman correlation coefficient, 0.66; P<0.001). Boys were more likely than girls to have disorders of phenotypic heterogeneity (P<0.001), and mothers were more likely than fathers to transmit second-site copy-number variants to their offspring (P=0.02).

CONCLUSIONS

Multiple, large copy-number variants, including those of unknown pathogenic significance, compound to result in a severe clinical presentation, and secondary copy-number variants are preferentially transmitted from maternal carriers. (Funded by the Simons Foundation Autism Research Initiative and the National Institutes of Health.).

Subtelomeric deletion of chromosome 10p15.3: clinical findings and molecular cytogenetic characterization

We describe 19 unrelated individuals with submicroscopic deletions involving 10p15.3 characterized by chromosomal microarray (CMA). Interestingly, to our knowledge, only two individuals with isolated, submicroscopic 10p15.3 deletion have been reported to date; however, only limited clinical information is available for these probands and the deleted region has not been molecularly mapped. Comprehensive clinical history was obtained for 12 of the 19 individuals described in this study. Common features among these 12 individuals include: cognitive/behavioral/developmental differences (11/11), speech delay/language disorder (10/10), motor delay (10/10), craniofacial dysmorphism (9/12), hypotonia (7/11), brain anomalies (4/6) and seizures (3/7). Parental studies were performed for nine of the 19 individuals; the 10p15.3 deletion was de novo in seven of the probands, not maternally inherited in one proband and inherited from an apparently affected mother in one proband. Molecular mapping of the 19 individuals reported in this study has identified two genes, ZMYND11 (OMIM 608668) and DIP2C (OMIM 611380; UCSC Genome Browser), mapping within 10p15.3 which are most commonly deleted. Although no single gene has been identified which is deleted in all 19 individuals studied, the deleted region in all but one individual includes ZMYND11 and the deleted region in all but one other individual includes DIP2C. There is not a clearly identifiable phenotypic difference between these two individuals and the size of the deleted region does not generally predict clinical features. Little is currently known about these genes complicating a direct genotype/phenotype correlation at this time. These data however, suggest that ZMYND11 and/or DIP2C haploinsufficiency contributes to the clinical features associated with 10p15 deletions in probands described in this study.