The clinical utility and costs of whole-genome sequencing to detect cancer susceptibility variants-a multi-site prospective cohort study.

BACKGROUND: Many families and individuals do not meet criteria for a known hereditary cancer syndrome but display unusual clusters of cancers. These families may carry pathogenic variants in cancer predisposition genes and be at higher risk for developing cancer. METHODS: This multi-centre prospective study recruited 195 cancer-affected participants suspected to have a hereditary cancer syndrome for whom previous clinical targeted genetic testing was either not informative or not available. To identify pathogenic disease-causing variants explaining participant presentation, germline whole-genome sequencing (WGS) and a comprehensive cancer virtual gene panel analysis were undertaken. RESULTS: Pathogenic variants consistent with the presenting cancer(s) were identified in 5.1% (10/195) of participants and pathogenic variants considered secondary findings with potential risk management implications were identified in another 9.7% (19/195) of participants. Health economic analysis estimated the marginal cost per case with an actionable variant was significantly lower for upfront WGS with virtual panel ($8744AUD) compared to standard testing followed by WGS ($24,894AUD). Financial analysis suggests that national adoption of diagnostic WGS testing would require a ninefold increase in government annual expenditure compared to conventional testing. CONCLUSIONS: These findings make a case for replacing conventional testing with WGS to deliver clinically important benefits for cancer patients and families. The uptake of such an approach will depend on the perspectives of different payers on affordability.

Functional and clinical studies reveal pathophysiological complexity of CLCN4-related neurodevelopmental condition.

Missense and truncating variants in the X-chromosome-linked CLCN4 gene, resulting in reduced or complete loss-of-function (LOF) of the encoded chloride/proton exchanger ClC-4, were recently demonstrated to cause a neurocognitive phenotype in both males and females. Through international clinical matchmaking and interrogation of public variant databases we assembled a database of 90 rare CLCN4 missense variants in 90 families: 41 unique and 18 recurrent variants in 49 families. For 43 families, including 22 males and 33 females, we collated detailed clinical and segregation data. To confirm causality of variants and to obtain insight into disease mechanisms, we investigated the effect on electrophysiological properties of 59 of the variants in Xenopus oocytes using extended voltage and pH ranges. Detailed analyses revealed new pathophysiological mechanisms: 25% (15/59) of variants demonstrated LOF, characterized by a "shift" of the voltage-dependent activation to more positive voltages, and nine variants resulted in a toxic gain-of-function, associated with a disrupted gate allowing inward transport at negative voltages. Functional results were not always in line with in silico pathogenicity scores, highlighting the complexity of pathogenicity assessment for accurate genetic counselling. The complex neurocognitive and psychiatric manifestations of this condition, and hitherto under-recognized impacts on growth, gastrointestinal function, and motor control are discussed. Including published cases, we summarize features in 122 individuals from 67 families with CLCN4-related neurodevelopmental condition and suggest future research directions with the aim of improving the integrated care for individuals with this diagnosis.

Further heterogeneity in Silver-Russell syndrome: PLAG1 deletion in association with a complex chromosomal rearrangement.

Silver-Russell syndrome (SRS) is a rare genetic condition primarily characterized by growth restriction and facial dysmorphisms. While hypomethylation of H19/IGF2:IG-DMR (imprinting control region 1 [IC1]) located at 11p15.5 and maternal uniparental disomy of chromosome 7 (upd[7]mat) are the most common genetic mechanisms responsible for SRS, the expanding body of literature describing alternative causative variants suggests SRS is a highly heterogeneous condition, also involving variation in the HMGA2-PLAG1-IGF2 pathway. We report a familial PLAG1 deletion in association with a complex chromosomal rearrangement. We describe two siblings with differing unbalanced chromosomal rearrangements inherited from a mother with a 5-breakpoint balanced complex rearrangement involving chromosomes 2, 8, and 21. The overlapping but diverse phenotypes in the siblings were characterized by shared SRS-like features, underlined by a PLAG1 whole gene deletion. Genetic analysis and interpretation was further complicated by a meiotic recombination event occurring in one of the siblings. This family adds to the limited literature available on PLAG1-related SRS. We have reviewed all currently known cases aiming to define the associated phenotype and guide future genetic testing strategies. The heterogeneity of SRS is further expanded by the involvement of complex cytogenomic abnormalities, imposing requirements for a comprehensive approach to testing and genetic counseling.

Implementing gene curation for hereditary cancer susceptibility in Australia: achieving consensus on genes with clinical utility.

BACKGROUND: The strength of evidence supporting the validity of gene-disease relationships is variable. Hereditary cancer has the additional complexity of low or moderate penetrance for some confirmed disease-associated alleles. METHODS: To promote national consistency in interpretation of hereditary cancer/tumour gene test results, we requested opinions of representatives from Australian Family Cancer Clinics regarding the clinical utility of 157 genes initially collated for a national research project. Viewpoints were sought by initial survey, face-to-face workshop and follow-up survey. Subsequent review was undertaken by the eviQ Cancer Genetics Reference Committee, a national resource providing evidence-based and consensus-driven cancer treatment protocols. RESULTS: Genes were categorised by clinical actionability as: relevant for testing on presentation of common cancer/tumour types (n=45); relevant for testing in the context of specific rare phenotypes (n=74); insufficient clinical utility (n=34) or contentious clinical utility (n=3). Opinions for several genes altered during the study time frame, due to new information. CONCLUSION: Through an iterative process, consensus was achieved on genes with clinical utility for hereditary cancer/tumour conditions in the Australian setting. This study highlighted need for regular review of gene-disease lists, a role assumed in Australia for hereditary cancer/tumour predisposition genes by the eviQ Cancer Genetics Reference Committee.

A flexible computational pipeline for research analyses of unsolved clinical exome cases.

Exome sequencing has enabled molecular diagnoses for rare disease patients but often with initial diagnostic rates of ~25-30%. Here we develop a robust computational pipeline to rank variants for reassessment of unsolved rare disease patients. A comprehensive web-based patient report is generated in which all deleterious variants can be filtered by gene, variant characteristics, OMIM disease and Phenolyzer scores, and all are annotated with an ACMG classification and links to ClinVar. The pipeline ranked 21/34 previously diagnosed variants as top, with 26 in total ranked ≤7th, 3 ranked ≥13th; 5 failed the pipeline filters. Pathogenic/likely pathogenic variants by ACMG criteria were identified for 22/145 unsolved cases, and a previously undefined candidate disease variant for 27/145. This open access pipeline supports the partnership between clinical and research laboratories to improve the diagnosis of unsolved exomes. It provides a flexible framework for iterative developments to further improve diagnosis.

RLIM Is a Candidate Dosage-Sensitive Gene for Individuals with Varying Duplications of Xq13, Intellectual Disability, and Distinct Facial Features.

Interpretation of the significance of maternally inherited X chromosome variants in males with neurocognitive phenotypes continues to present a challenge to clinical geneticists and diagnostic laboratories. Here we report 14 males from 9 families with duplications at the Xq13.2-q13.3 locus with a common facial phenotype, intellectual disability (ID), distinctive behavioral features, and a seizure disorder in two cases. All tested carrier mothers had normal intelligence. The duplication arose de novo in three mothers where grandparental testing was possible. In one family the duplication segregated with ID across three generations. RLIM is the only gene common to our duplications. However, flanking genes duplicated in some but not all the affected individuals included the brain-expressed genes NEXMIF, SLC16A2, and the long non-coding RNA gene FTX. The contribution of the RLIM-flanking genes to the phenotypes of individuals with different size duplications has not been fully resolved. Missense variants in RLIM have recently been identified to cause X-linked ID in males, with heterozygous females typically having normal intelligence and highly skewed X chromosome inactivation. We detected consistent and significant increase of RLIM mRNA and protein levels in cells derived from seven affected males from five families with the duplication. Subsequent analysis of MDM2, one of the targets of the RLIM E3 ligase activity, showed consistent downregulation in cells from the affected males. All the carrier mothers displayed normal RLIM mRNA levels and had highly skewed X chromosome inactivation. We propose that duplications at Xq13.2-13.3 including RLIM cause a recognizable but mild neurocognitive phenotype in hemizygous males.

The variability of SMARCA4-related Coffin-Siris syndrome: Do nonsense candidate variants add to milder phenotypes?

SMARCA4 encodes a central ATPase subunit in the BRG1-/BRM-associated factors (BAF) or polybromo-associated BAF (PBAF) complex in humans, which is responsible in part for chromatin remodeling and transcriptional regulation. Variants in this and other genes encoding BAF/PBAF complexes have been implicated in Coffin-Siris Syndrome, a multiple congenital anomaly syndrome classically characterized by learning and developmental differences, coarse facial features, hypertrichosis, and underdevelopment of the fifth digits/nails of the hands and feet. Individuals with SMARCA4 variants have been previously reported and appear to display a variable phenotype. We describe here a cohort of 15 unrelated individuals with SMARCA4 variants from the Coffin-Siris syndrome/BAF pathway disorders registry who further display variability in severity and degrees of learning impairment and health issues. Within this cohort, we also report two individuals with novel nonsense variants who appear to have a phenotype of milder learning/behavioral differences and no organ-system involvement.

New insights into DNA methylation signatures: SMARCA2 variants in Nicolaides-Baraitser syndrome.

BACKGROUND: Nicolaides-Baraitser syndrome (NCBRS) is a neurodevelopmental disorder caused by pathogenic sequence variants in SMARCA2 which encodes the catalytic component of the chromatin remodeling BAF complex. Pathogenic variants in genes that encode epigenetic regulators have been associated with genome-wide changes in DNA methylation (DNAm) in affected individuals termed DNAm signatures. METHODS: Genome-wide DNAm was assessed in whole-blood samples from the individuals with pathogenic SMARCA2 variants and NCBRS diagnosis (n = 8) compared to neurotypical controls (n = 23) using the Illumina MethylationEPIC array. Differential methylated CpGs between groups (DNAm signature) were identified and used to generate a model enabling classification variants of uncertain significance (VUS; n = 9) in SMARCA2 as "pathogenic" or "benign". A validation cohort of NCBRS cases (n = 8) and controls (n = 96) demonstrated 100% model sensitivity and specificity. RESULTS: We identified a DNAm signature of 429 differentially methylated CpG sites in individuals with NCBRS. The genes to which these CpG sites map are involved in cell differentiation, calcium signaling, and neuronal function consistent with NCBRS pathophysiology. DNAm model classifications of VUS were concordant with the clinical phenotype; those within the SMARCA2 ATPase/helicase domain classified as "pathogenic". A patient with a mild neurodevelopmental NCBRS phenotype and a VUS distal to the ATPase/helicase domain did not score as pathogenic, clustering away from cases and controls. She demonstrated an intermediate DNAm profile consisting of one subset of signature CpGs with methylation levels characteristic of controls and another characteristic of NCBRS cases; each mapped to genes with ontologies consistent with the patient's unique clinical presentation. CONCLUSIONS: Here we find that a DNAm signature of SMARCA2 pathogenic variants in NCBRS maps to CpGs relevant to disorder pathophysiology, classifies VUS, and is sensitive to the position of the variant in SMARCA2. The patient with an intermediate model score demonstrating a unique genotype-epigenotype-phenotype correlation underscores the potential utility of this signature as a functionally relevant VUS classification system scalable beyond binary "benign" versus "pathogenic" scoring. This is a novel feature of DNAm signatures that could enable phenotypic predictions from genotype data. Our findings also demonstrate that DNAm signatures can be domain-specific, highlighting the precision with which they can reflect genotypic variation.

Improved Diagnosis and Care for Rare Diseases through Implementation of Precision Public Health Framework.

Public health relies on technologies to produce and analyse data, as well as effectively develop and implement policies and practices. An example is the public health practice of epidemiology, which relies on computational technology to monitor the health status of populations, identify disadvantaged or at risk population groups and thereby inform health policy and priority setting. Critical to achieving health improvements for the underserved population of people living with rare diseases is early diagnosis and best care. In the rare diseases field, the vast majority of diseases are caused by destructive but previously difficult to identify protein-coding gene mutations. The reduction in cost of genetic testing and advances in the clinical use of genome sequencing, data science and imaging are converging to provide more precise understandings of the 'person-time-place' triad. That is: who is affected (people); when the disease is occurring (time); and where the disease is occurring (place). Consequently we are witnessing a paradigm shift in public health policy and practice towards 'precision public health'.Patient and stakeholder engagement has informed the need for a national public health policy framework for rare diseases. The engagement approach in different countries has produced highly comparable outcomes and objectives. Knowledge and experience sharing across the international rare diseases networks and partnerships has informed the development of the Western Australian Rare Diseases Strategic Framework 2015-2018 (RD Framework) and Australian government health briefings on the need for a National plan.The RD Framework is guiding the translation of genomic and other technologies into the Western Australian health system, leading to greater precision in diagnostic pathways and care, and is an example of how a precision public health framework can improve health outcomes for the rare diseases population.Five vignettes are used to illustrate how policy decisions provide the scaffolding for translation of new genomics knowledge, and catalyze transformative change in delivery of clinical services. The vignettes presented here are from an Australian perspective and are not intended to be comprehensive, but rather to provide insights into how a new and emerging 'precision public health' paradigm can improve the experiences of patients living with rare diseases, their caregivers and families.The conclusion is that genomic public health is informed by the individual and family needs, and the population health imperatives of an early and accurate diagnosis; which is the portal to best practice care. Knowledge sharing is critical for public health policy development and improving the lives of people living with rare diseases.

Initiating an undiagnosed diseases program in the Western Australian public health system.

BACKGROUND: New approaches are required to address the needs of complex undiagnosed diseases patients. These approaches include clinical genomic diagnostic pipelines, utilizing intra- and multi-disciplinary platforms, as well as specialty-specific genomic clinics. Both are advancing diagnostic rates. However, complementary cross-disciplinary approaches are also critical to address those patients with multisystem disorders who traverse the bounds of multiple specialties and remain undiagnosed despite existing intra-specialty and genomic-focused approaches. The diagnostic possibilities of undiagnosed diseases include genetic and non-genetic conditions. The focus on genetic diseases addresses some of these disorders, however a cross-disciplinary approach is needed that also simultaneously addresses other disorder types. Herein, we describe the initiation and summary outcomes of a public health system approach for complex undiagnosed patients - the Undiagnosed Diseases Program-Western Australia (UDP-WA). RESULTS: Briefly the UDP-WA is: i) one of a complementary suite of approaches that is being delivered within health service, and with community engagement, to address the needs of those with severe undiagnosed diseases; ii) delivered within a public health system to support equitable access to health care, including for those from remote and regional areas; iii) providing diagnoses and improved patient care; iv) delivering a platform for in-service and real time genomic and phenomic education for clinicians that traverses a diverse range of specialties; v) retaining and recapturing clinical expertise; vi) supporting the education of junior and more senior medical staff; vii) designed to integrate with clinical translational research; and viii) is supporting greater connectedness for patients, families and medical staff. CONCLUSION: The UDP-WA has been initiated in the public health system to complement existing clinical genomic approaches; it has been targeted to those with a specific diagnostic need, and initiated by redirecting existing clinical and financial resources. The UDP-WA supports the provision of equitable and sustainable diagnostics and simultaneously supports capacity building in clinical care and translational research, for those with undiagnosed, typically rare, conditions.

Novel application of luciferase assay for the in vitro functional assessment of KAL1 variants in three females with septo-optic dysplasia (SOD).

KAL1 is implicated in 5% of Kallmann syndrome cases, a disorder which genotypically overlaps with septo-optic dysplasia (SOD). To date, a reporter-based assay to assess the functional consequences of KAL1 mutations is lacking. We aimed to develop a luciferase assay for novel application to functional assessment of rare KAL1 mutations detected in a screen of 422 patients with SOD. Quantitative analysis was performed using L6-myoblasts stably expressing FGFR1, transfected with a luciferase-reporter vector containing elements of the FGF-responsive osteocalcin promoter. The two variants assayed [p.K185N, p.P291T], were detected in three females with SOD (presenting with optic nerve hypoplasia, midline and pituitary defects). Our novel assay revealed significant decreases in transcriptional activity [p.K185N: 21% (p < 0.01); p.P291T: 40% (p < 0.001)]. Our luciferase-reporter assay, developed for assessment of KAL1 mutations, determined that two variants in females with hypopituitarism/SOD are loss-of-function; demonstrating that this assay is suitable for quantitative assessment of mutations in this gene.

Ovarian sex cord-stromal tumors in patients with probable or confirmed germline DICER1 mutations.

The DICER1 gene encodes an endoribonuclease involved in the production of mature microRNAs which regulates gene expression through several mechanisms. Recent studies have demonstrated somatic mutations in DICER1 in approximately 60% of ovarian Sertoli-Leydig cell tumors. Furthermore, patients with germline mutations in DICER1 are predisposed to developing a range of rare neoplasms including ovarian sex cord-stromal tumors most of which have been classified as Sertoli-Leydig cell tumor. However, the histologic features of these tumors have not been reported in detail. We describe the morphologic and immunophenotypic findings of 4 sex cord-stromal tumors arising in patients with proven or likely germline DICER1 mutations including 3 individuals from 1 family. Three tumors showed similar appearances characterized by marked architectural and cytologic heterogeneity including sertoliform, juvenile granulosa cell tumor-like, and unclassifiable elements. The remaining case mainly showed heterologous mucinous epithelial and neuroendocrine differentiation with only a minor intermediate-grade Sertoli cell component. This tumor and one of the 3 former cases arose in related patients with identical germline DICER1 mutations indicating that additional factors influence tumor morphology. All tumors were positive for steroidogenic factor-1 and FOXL2 on immunohistochemical analysis, whereas there was more variable expression of inhibin, calretinin, CD56, CD99, and hormone receptors. The present small series suggests that some ovarian Sertoli-Leydig cell tumor associated with germline DICER1 mutations may show distinctive histologic features in particular admixed Sertoli cell and juvenile granulosa cell tumor-like features. Larger studies are required to establish whether heterologous elements are also a more common feature of these tumors.

Mutations in STAMBP, encoding a deubiquitinating enzyme, cause microcephaly-capillary malformation syndrome.

Microcephaly-capillary malformation (MIC-CAP) syndrome is characterized by severe microcephaly with progressive cortical atrophy, intractable epilepsy, profound developmental delay and multiple small capillary malformations on the skin. We used whole-exome sequencing of five patients with MIC-CAP syndrome and identified recessive mutations in STAMBP, a gene encoding the deubiquitinating (DUB) isopeptidase STAMBP (STAM-binding protein, also known as AMSH, associated molecule with the SH3 domain of STAM) that has a key role in cell surface receptor-mediated endocytosis and sorting. Patient cell lines showed reduced STAMBP expression associated with accumulation of ubiquitin-conjugated protein aggregates, elevated apoptosis and insensitive activation of the RAS-MAPK and PI3K-AKT-mTOR pathways. The latter cellular phenotype is notable considering the established connection between these pathways and their association with vascular and capillary malformations. Furthermore, our findings of a congenital human disorder caused by a defective DUB protein that functions in endocytosis implicates ubiquitin-conjugate aggregation and elevated apoptosis as factors potentially influencing the progressive neuronal loss underlying MIC-CAP syndrome.

The effect of height, weight and head circumference on gross motor development in achondroplasia.

PURPOSE: This study aimed to investigate whether height, weight, head circumference and/or relationships between these factors are associated with gross motor milestone acquisition in children with achondroplasia. METHOD: Population-based data regarding timing of major gross motor milestones up to 5 years were correlated with height, weight and head circumference at birth and 12 months in 48 children with achondroplasia born in Australia and New Zealand between 2000 and 2009. RESULTS: Although as a group children with achondroplasia showed delayed gross motor skill acquisition, within group differences in height, weight or head circumference did not appear to influence timing of gross motor skills before 5 years. The exception was lie to sit transitioning, which appears likely to occur earlier if the child is taller and heavier at 12 months, and later if the child has significant head-to-body disproportion. CONCLUSIONS: This is the first study to investigate the relationship between common musculoskeletal impairments associated with achondroplasia and timing of gross motor achievement. Identification of the musculoskeletal factors that exacerbate delays in transitioning from lying to sitting will assist clinicians to provide more proactive assessment, advice and intervention regarding motor skill acquisition for this population.

Development in children with achondroplasia: a prospective clinical cohort study.

AIM: Achondroplasia is characterized by delays in the development of communication and motor skills. While previously reported developmental profiles exist across gross motor, fine motor, feeding, and communication skills, there has been no prospective study of development across multiple areas simultaneously. METHOD: This Australasian population-based study utilized a prospective questionnaire to quantify developmental data for skills in children born from 2000 to 2009. Forty-eight families from Australia and New Zealand were asked to report every 3 months on their child's attainment of 41 milestones. Results include reference to previously available prospective information. RESULTS: Information from questionnaires was used to develop an achondroplasia-specific developmental recording form. The 25th, 50th, 75th, and 90th centiles were plotted to offer clear guidelines for development across gross motor, fine motor, feeding, and communication skills in children with achondroplasia. INTERPRETATIONS: Consistent with results from previous research, children with achondroplasia are delayed in development of gross motor and ambulatory skills. Young children with achondroplasia demonstrate a number of unique movement strategies that appear compensatory for the biomechanical changes. While delays were seen in development of later communication items, there were fewer delays seen across development of early communication, fine motor, and feeding skills.

Medical management of children with achondroplasia: evaluation of an Australasian cohort aged 0-5 years.

AIMS: Achondroplasia is the most common form of osteochondrodysplasia and is associated with a number of life-threatening complications. The complexity of the condition led to the development of Heath Supervision Guidelines published by the American Academy of Pediatrics in 1995 and revised in 2005. There remains limited population-based information on utilisation of medical and therapy services for children with achondroplasia. Increased information regarding use of these services will assist in future service development. METHODS: Data regarding frequency and timing of medical and allied health consultations, investigations and interventions were collected from 53 Australasian families via questionnaire, based on recommendations of the Health Supervision Guidelines, an expert reference group and literature review. RESULTS: Rates varied with age for medical consultations (geneticist, paediatric rehabilitation physician/paediatrician, respiratory physician, orthopaedic consultant, neurologist, neurosurgeon), medical investigations (sleep study, magnetic resonance imaging/computed tomography), operative procedures (brain-stem decompression, tonsillectomy/adenoidectomy, shunt insertion, shunt revision and insertion of grommets) and allied health consultations (physiotherapist, occupational therapist, speech pathologist, dietician and orthotist). CONCLUSIONS: Access to geneticists and paediatricians within the first year is high as recommended by the 2005 American Academy of Pediatrics guidelines. Utilisation of craniocervical magnetic resonance imaging/computed tomography, polysomnography studies and formal speech review appears low, reflecting more emphasis on clinical monitoring for cervical cord compression and disordered sleep breathing as well as possible difficulties in accessing services for polysomnography and speech pathology. Grommet insertion, tonsillectomy/adenoidectomy and cervicomedullary decompression rates are similar to results reported previously. Over half of the children accessed physiotherapy and/or occupational therapy services, warranting consideration of these professionals in future guideline recommendations.

Functional performance in young Australian children with achondroplasia.

AIM: The aim of this study was to determine population-specific developmental milestones for independence in self-care, mobility, and social cognitive skills in children with achondroplasia, the most common skeletal dysplasia. METHODS: Population-based recruitment from October 2008 to October 2010 identified 44 Australian children with achondroplasia aged 3 to 7 years. Consenting parents of 35 children (16 males, 19 females 14 aged 3y; 12 aged 5y; nine aged 7y) reported their child's self-care, mobility, and social cognition function using the Functional Independence Measure for Children (WeeFIM-II) at the ages of 3 (n=14), 5 (n=12), or 7 (n=9) years. Children were excluded from the study if they had an additional neurological or musculoskeletal condition. RESULTS: Functioning improved in children with achondroplasia between the ages of 3 and 5 years, but not subsequently. Milestones in the achondroplasia group were delayed across all ages and domains compared with normative reference data. Children with achondroplasia required greater caregiver assistance for self-care and mobility skills than typically developing children based on normative data. Social cognition appeared to be an area of relative strength. INTERPRETATION: Children up to 7 years of age with achondroplasia show delayed milestone acquisition and a greater need for caregiver assistance for all domains. As functional delays are likely to be related to common musculoskeletal impairments associated with achondroplasia, access to physiotherapists, occupational therapists, and speech and language pathologists skilled in achondroplasia management may assist children and families to become more independent, particularly around the time of starting school.

Developmental milestones in infants and young Australasian children with achondroplasia.

BACKGROUND: Achondroplasia, the most common form of chondrodysplasia (inherited skeletal dysplasia), is characterized by a significant delay in the development of communication and motor skills, particularly during the first 2 years. Although some information regarding timing of development for children with achondroplasia is available, no study has evaluated simultaneously the pattern of skill development across multiple key developmental areas. METHOD: This study used a retrospective questionnaire to quantify developmental data on milestone achievement. Twenty families of children with achondroplasia throughout Australia and New Zealand were asked to document age of acquisition for 41 gross motor, fine motor, and communication and feeding milestones. More than one half of the items assessed were milestones identified in the Australian State Government Personal Health Record Books. The results are compared with previously available information regarding development of motor skills by a cohort of American children with achondroplasia. RESULTS: Although the results support previously reported delays in gross motor and communication skill development, fine motor development does not seem to be as delayed as previously suggested. Information on development of self-feeding skills is presented for the first time and occurs later in this group than the typically developing population. We describe 2 distinctive and previously unreported methods of transitioning between static positions commonly used by children with achondroplasia. CONCLUSION: Delays were reported across gross motor and communication and feeding skills but were not observed during development of fine motor skills. Additional information is also offered regarding a variety of unusual movement strategies demonstrated by young children with achondroplasia.

A case of 3q29 microdeletion with novel features and a review of cytogenetically visible terminal 3q deletions.

A further case of 3q29 deletion, in a 13-year-old boy, is described and compared with previous reports. Our case shares a number of dysmorphic and neurodevelopmental features with previously reported individuals with 3q29 microdeletion and is the second reported case with deceleration in head growth--which may be a useful diagnostic clue. Novel features, which may expand the phenotype, include nasal voice, six lumbar vertebrae, lower limb contractures and cerebral sigmoid venous thrombosis. Additionally, cases with cytogenetically visible terminal 3q deletions are reviewed.