David Coman

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Verified

David verified their affiliation via an institutional email.

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• MBBS MPhil FRACP
• Professor at Queensland Health

Background Only half of individuals with suspected rare diseases receive a genetic diagnosis following genomic testing. A genetic diagnosis allows access to appropriate care, restores reproductive confidence and reduces the number of potentially unnecessary interventions. A major barrier is the lack of disease agnostic functional tests suitable for...

Ataxia-Telangiectasia (A-T) is a very rare multisystem disease of DNA repair, associated with progressive disabling neurological symptoms, respiratory failure, immunodeficiency and cancer predisposition, leading to premature death. There are no curative treatments available for A-T but clinical trials have begun. A major limiting factor in effectiv...

Renal chloride metabolism is currently poorly understood but may serve as both a diagnostic and a treatment approach for acute kidney injury. We investigated whether plasma chloride, ammonia and glutamine as well as urinary chloride, ammonium and glutamine concentrations may serve as markers for acute kidney injury in paediatric patients. We conduc...

Medical image synthesis generates additional imaging modalities that are costly, invasive or harmful to acquire, which helps to facilitate the clinical workflow. When training pairs are substantially misaligned (e.g., lung MRI-CT pairs with respiratory motion), accurate image synthesis remains a critical challenge. Recent works explored the directi...

Around 60% of individuals with neurodevelopmental disorders (NDD) remain undiagnosed after comprehensive genetic testing, primarily of protein-coding genes¹. Large genome-sequenced cohorts are improving our ability to discover new diagnoses in the non-coding genome. Here we identify the non-coding RNA RNU4-2 as a syndromic NDD gene. RNU4-2 encodes...

Understanding the impact of splicing and nonsense variants on RNA is crucial for the resolution of variant classification as well as their suitability for precision medicine interventions. This is primarily enabled through RNA studies involving transcriptomics followed by targeted assays using RNA isolated from clinically accessible tissues (CATs)...

TIMM50 is a core subunit of the TIM23 complex, the mitochondrial inner membrane translocase responsible for the import of pre-sequence-containing precursors into the mitochondrial matrix and inner membrane. Here we describe a mitochondrial disease patient who is homozygous for a novel variant in TIMM50 and establish the first proteomic map of mitoc...

Neurodevelopmental disorders (NDDs) result from impaired development and functioning of the brain. Here, we identify loss-of-function (LoF) variation in ZFHX3 as a cause for syndromic intellectual disability (ID). ZFHX3 is a zinc-finger homeodomain transcription factor involved in various biological processes, including cell differentiation and tum...

Classic galactosemia (CG, OMIM #230400, ORPHA: 79,239) is a hereditary disorder of galactose metabolism that, despite treatment with galactose restriction, affects brain function in 85% of the patients. Problems with cognitive function, neuropsychological/social emotional difficulties, neurological symptoms, and abnormalities in neuroimaging and el...

Purpose. Families living with mitochondrial diseases (MD) often endure prolonged diagnostic journeys and invasive testing, yet many remain without a molecular diagnosis. Through a national team of clinicians, diagnostic, and research scientists, the Australian Genomics Mitochondrial disease flagship conducted a prospective study to identify the dia...

Background/objectives: Ataxia telangiectasia (A-T) is a multiorgan disorder with increased vulnerability to cancer. Despite this increased cancer risk, there are no widely accepted guidelines for cancer surveillance in people affected by A-T. We aimed to understand the current international practice regarding cancer surveillance in A-T and agreed-...

Accurate diagnosis for patients living with neurodevelopmental disorders is often met with numerous challenges, related to the ambiguity of findings and lack of specificity in genetic variants leading to pathology. Genome-wide DNA methylation analysis has been used to develop highly sensitive and specific 'episignatures' as biomarkers capable of di...

Purpose: The study aimed to define the genotypic and phenotypic spectrum of reversible acute liver failure (ALF) of infancy resulting from biallelic pathogenic TRMU variants and to determine the role of cysteine supplementation in its treatment. Methods: Individuals with biallelic (likely) pathogenic variants in TRMU were studied through an inte...

Childhood apraxia of speech (CAS), the prototypic severe childhood speech disorder, is characterized by motor programming and planning deficits. Genetic factors make substantive contributions to CAS aetiology, with a monogenic pathogenic variant identified in a third of cases, implicating around 20 single genes to date. Here we aimed to identify mo...

3‐Methylglutaconyl‐CoA hydratase deficiency (MGA1) is a defect in leucine catabolism, which causes the accumulation of urinary 3‐methylglutaconate, with or without 3‐hydroxyisovalerate and 3‐methylglutarate. It is an ultra‐rare condition, with <30 cases published in the literature. It is unclear whether the clinical features seen in reported patien...

Hereditary spastic paraplegia 56 (SPG56) is an extremely rare autosomal recessive disorder caused by mutations in the CYP2U1 gene, involved in fatty acid metabolism. SPG56 causes progressive spasticity in upper and lower limbs, though due to the rarity of this subtype of spastic paraplegia, the molecular causes remain unclear and no treatment or cu...

N‐acetylglutamate synthase (NAGS) deficiency is a rare autosomal recessive disorder, which results in the inability to activate the key urea cycle enzyme, carbamoylphosphate synthetase 1 (CPS1). Patients often suffer life‐threatening episodes of hyperammonaemia, both in the neonatal period and also at subsequent times of catabolic stress. Because N...

Childhood apraxia of speech (CAS), the prototypic severe childhood speech disorder, is characterized by motor programming and planning deficits. Genetic factors make substantive contributions to CAS aetiology, with a monogenic pathogenic variant identified in a third of cases, implicating around 20 single genes to date. Here we ascertained 70 unrel...

The ataxia-telangiectasia mutated (ATM) protein kinase is, as the name implies, mutated in the human genetic disorder ataxia-telangiectasia (A-T). This protein has its “finger in many pies”, being responsible for the phosphorylation of many thousands of proteins in different signaling pathways in its role in protecting the cell against a variety of...

Background Intronic WT1 mutations are usually causative of Frasier syndrome with focal segmental glomerulosclerosis as the characteristic nephropathy. Membranoproliferative glomerulonephritis is not commonly associated with disorders of sex development but has been recently identified as a WT1 -associated nephropathy, but usually in cases of exonic...

Background and Objectives Purine-rich element-binding protein A ( PURA ) gene encodes Pur-α, a conserved protein essential for normal postnatal brain development. Recently, a PURA syndrome characterized by intellectual disability, hypotonia, epilepsy, and dysmorphic features was suggested. The aim of this study was to define and expand the phenotyp...

Phenylketonuria (PKU) is an inherited disorder of phenylalanine (Phe) metabolism caused by a mutation in the PAH gene coding for the enzyme phenylalanine hydroxylase (PAH). Sapropterin dihydrochloride is a synthetic form of tetrahydrobiopterin, the natural cofactor for PAH. Sapropterin-responsive patients with PKU have demonstrated increased dietar...

Objective: ATM, the protein defective in the human genetic disorder, ataxia telangiectasia (A-T) plays a central role in the response to DNA double strand breaks (DSBs) and in protecting the cell against oxidative stress. We recently showed that A-T cells are hypersensitive to metabolic stress which can be accounted for by a failure to exhibit eff...

This document provides consensus-based recommendations for general physicians and primary care physicians who diagnose and manage patients with mitochondrial diseases (MDs). It builds on previous international guidelines,¹ with particular emphasis on clinical management in the Australian setting. This statement was prepared by a working group of me...

Smith‐Kingsmore Syndrome (SKS) is a rare genetic syndrome associated with megalencephaly, a variable intellectual disability, autism spectrum disorder, and MTOR gain of function variants. Only 30 patients with MTOR missense variants are published, including 14 (47%) with the MTOR c.5395G>A p.(Glu1799Lys) variant. Limited phenotypic data impacts the...

Mitochondrial diseases can be caused by pathogenic variants in nuclear or mitochondrial DNA-encoded genes that often lead to multisystemic symptoms and can have any mode of inheritance. Using a single test, Genome Sequencing (GS) can effectively identify variants in both genomes, but it has not yet been universally used as a first-line approach to...

Carnitine acyl-carnitine translocase deficiency (CACTD) is a rare autosomal recessive disorder of mitochondrial long-chain fatty-acid transport. Most patients present in the first 2 days of life, with hypoketotic hypoglycaemia, hyperammonaemia, cardiomyopathy or arrhythmia, hepatomegaly and elevated liver enzymes. Multi-centre international retrosp...

There is evidence that ATM mutated in ataxia-telangiectasia (A-T) plays a key role in protecting against mitochondrial dysfunction, the mechanism for which remains unresolved. We demonstrate here that ATM-deficient cells are exquisitely to sensitive to nutrient deprivation which can be explained by defective cross-talk between the endoplasmic retic...

Phosphoglucomutase 1 (PGM1) deficiency is a rare genetic disorder that affects glycogen metabolism, glycolysis, and protein glycosylation. Previously known as GSD XIV, it was recently reclassified as a congenital disorder of glycosylation, PGM1‐CDG. PGM1‐CDG usually manifests as a multisystem disease. Most patients present as infants with cleft pal...

Objective Families of children with phenylketonuria (PKU) report child emotional and behavioral problems, parenting stress, and parenting difficulties, which are associated with worse health-related quality of life. This study aimed to examine acceptability and feasibility of a brief, group-based parenting program (Healthy Living Triple P) for fami...

Loss-of-function mutations of the X-chromosome gene UPF3B cause male neurodevelopmental disorders (NDDs) via largely unknown mechanisms. We investigated initially by interrogating a novel synonymous UPF3B variant in a male with absent speech. In-silico and functional studies using cell lines derived from this individual show altered UPF3B RNA splic...

Background Up-regulation of hepatic delta-aminolevulinic acid synthase 1 (ALAS1), with resultant accumulation of delta-aminolevulinic acid (ALA) and porphobilinogen, is central to the pathogenesis of acute attacks and chronic symptoms in acute hepatic porphyria. Givosiran, an RNA interference therapy, inhibits ALAS1 expression. Methods In this dou...

Objective Determining the genetic basis of speech disorders provides insight into the neurobiology of human communication. Despite intensive investigation over the past 2 decades, the etiology of most speech disorders in children remains unexplained. To test the hypothesis that speech disorders have a genetic etiology, we performed genetic analysis...

Clinical characteristics Fumarate hydratase (FH) deficiency results in severe neonatal and early infantile encephalopathy that is characterized by poor feeding, failure to thrive, hypotonia, lethargy, and seizures. Dysmorphic facial features include frontal bossing, depressed nasal bridge, and widely spaced eyes. Many affected individuals are micro...

The utility of genome sequencing (GS) in the diagnosis of suspected pediatric mitochondrial disease (MD) was investigated. An Australian cohort of 40 pediatric patients with clinical features suggestive of MD were classified using the modified Nijmegen mitochondrial disease severity scoring into definite (17), probable (17), and possible (6) MD gro...

Clinical characteristics Squalene synthase deficiency (SQSD) is a rare inborn error of cholesterol biosynthesis with multisystem clinical manifestations similar to Smith-Lemli-Optiz syndrome. Key clinical features include facial dysmorphism, a generalized seizure disorder presenting in the neonatal period, nonspecific structural brain malformations...

COPA syndrome is a recently described autosomal dominant disorder with key immune dysregulation caused by defects within the COPA gene. These mutations lead to endoplasmic reticulum stress and autoimmune response with upregulation of Th17 cytokines. The clinical phenotype of COPA syndrome primarily comprised pulmonary disease, arthritis, and renal...

Objective This study aimed to assess the impact of phenylketonuria (PKU) and its treatment on parent and child health‐related quality of life (HRQoL) and to identify the parenting‐related correlates of parent and child HRQoL, as well as metabolic control. Methods Eighteen mothers of 2‐ to 12‐year‐old children with PKU participated and completed a...

Background: Phosphomannomutase 2 deficiency (PMM2-CDG) is the most common congenital disorder of glycosylation (CDG). Hypoglycemia has been reported in various CDG including PMM2-CDG. The frequency and etiology of hypoglycemia in PMM2-CDG are not well studied. Methods: We conducted a systematic review of the literature on genetically and/or bioc...

INTRODUCTION Acute Hepatic Porphyria (AHP) is a family of rare genetic diseases due to enzyme deficiencies in heme biosynthesis in the liver that can lead to neurovisceral attacks and chronic symptoms. (1, 2) AHP is also associated with multiple long-term complications, including neuropathy (3,4), hypertension (5,6), chronic kidney disease (7), and...

Coffin–Siris syndrome (CSS, MIM#135900) is a congenital disorder characterized by coarse facial features, intellectual disability, and hypoplasia of the fifth digit and nails. Pathogenic variants for CSS have been found in genes encoding proteins in the BAF (BRG1-associated factor) chromatin-remodeling complex. To date, more than 150 CSS patients w...

Supplementary Fig. 1: Western blot analysis of mitochondrial citrate carrier (CIC) alleles containing missense variants transfected into primary SLC25A1 −/−-deficient fibroblasts to confirm construct validity. A representative Western blot analysis of triplicate experiments is shown. CIC relative abundance was analyzed by Western blotting using ant...

The rare autoinflammatory disease mevalonate kinase deficiency (MKD, which includes HIDS and mevalonic aciduria) is caused by recessive, pathogenic variants in the MVK gene encoding mevalonate kinase. Deficiency of this enzyme decreases the synthesis of isoprenoid lipids and thus prevents the normal post-translational prenylation of small GTPase pr...

She continued to have brief episodes of ventricular tachycardia (VT) with recurrent pulseless arrest. Her serum potassium was normal during this time, ranging from 3.8-5.0 mmol/l. She had a prolonged hospitalization course due to cardiac arrhythmia and subsequently had placement of dual chamber implantable cardioverter defibrillator (ICD). Prior to...

Squalene Synthase Deficiency: Clinical, Biochemical, and Molecular Characterization of a Defect in Cholesterol Biosynthesis

Cholesterol plays an essential role in normal embryogenesis and perturbations in its de novo synthesis are responsible for organ malformations in the cholesterol biosynthesis defects. Ten distinct inherited disorders have been linked to different enzyme defects in the isoprenoid/cholesterol biosynthetic pathway: mevalonic aciduria, hyperimmunoglobu...

Phosphomannomutase 2 (PMM2‐CDG) is the most common congenital disorder of N‐glycosylation and is caused by a deficient PMM2 activity. The clinical presentation and the onset of PMM2‐CDG vary among affected individuals ranging from a severe antenatal presentation with multisystem involvement to mild adulthood presentation limited to minor neurologic...

Pathogenic de novo variants in the X‐linked gene SLC35A2 encoding the major Golgi‐localized UDP‐galactose transporter required for proper protein and lipid glycosylation cause a rare type of congenital disorder of glycosylation known as SLC35A2‐CDG (formerly CDG‐IIm). To date, twenty‐nine unique de novo variants from thirty‐two unrelated individual...

Key Clinical Message We report a novel 9q31.2q32 (chr9: 109195179‐113974353, hg 18) microdeletion characterized by fatigue, muscle cramps, short stature, delayed puberty, sensorineural hearing loss, and mild developmental delay. Overlapping microdeletions reported in this region also demonstrate facial dysmorphism, skeletal anomalies, cleft palate,...

Leber Hereditary Optic Neuropathy is an inherited optic neuropathy caused by mitochondrial DNA point mutations leading to sudden, painless loss of vision. We report a case of an 8-year-old boy presenting with a radiological phenotype of longitudinally extensive transverse myelitis on a background of severe visual impairment secondary to Leber Hered...

Hajdu-Cheney Syndrome (HSC) is a rare multisystem disease in which the phenotype involves acro-osteolysis, severe osteoporosis, short stature, wormian bones, facial dysmorphism, central neurological abnormalities, cardiovascular defects, and polycystic kidneys. We describe an infant with severe manifestations of HCS in whom congenital glaucoma was...

The SYNE1 (spectrin repeat-containing nuclear envelope protein 1) gene encodes a family of spectrin structural proteins that are associated with anchoring the plasma membrane to the actin cytoskeleton. SYNE1-related disease is most commonly reported in autosomal recessive spinocerebellar ataxia 8, which demonstrates variable age of onset with a med...

We describe a 4-year-old boy with developmental delay who was found to carry by clinical grade molecular cytogenetics a chromosome Xq26 microduplication. The report prompted a referral of the patient for possible X-linked acrogigantism (X-LAG), a well-defined condition (MIM300942) due to chromosomal microduplication of a nearby region. The patient...

Mendelian disorders of cholesterol biosynthesis typically result in multi-system clinical phenotypes, underlining the importance of cholesterol in embryogenesis and development. FDFT1 encodes for an evolutionarily conserved enzyme, squalene synthase (SS, farnesyl-pyrophosphate farnesyl-transferase 1), which catalyzes the first committed step in cho...

Microdeletions at 19p13.3 are rarely reported in the medical literature with significant phenotypic variability. Among the reported cases, common clinical manifestations have included developmental delay, facial dysmorphism, and hypotonia. Herein we described a child with a de novo 19p13.3 microdeletion, proximal to the reported cases of 19p13.3 mi...

Congenital disorders of glycosylation (CDG) are a rapidly growing family comprising >100 genetic diseases. Some 25 CDG are pure O-glycosylation defects. Even among this CDG subgroup, phenotypic diversity is broad, ranging from mild to severe poly-organ/system dysfunction. Ophthalmic manifestations are present in 60% of these CDG. The ophthalmic man...

Combined D-2- and L-2-hydroxyglutaric aciduria (D/L-2-HGA) is a devastating neurometabolic disorder, usually lethal in the first years of life. Autosomal recessive mutations in the SLC25A1 gene, which encodes the mitochondrial citrate carrier (CIC), were previously detected in patients affected with combined D/L-2-HGA. We showed that transfection o...

We describe mitochondrial trifunctional protein deficiency (MTPD) in two male siblings who presented with severe cardiomyopathy in infancy. The first sibling presented in severe cardiac failure at 6 months of age and succumbed soon after. The second sibling came to attention after newborn screening identified a possible fatty acid oxidation defect....

X-linked lissencephaly with abnormal genitalia is a rare and devastating syndrome. The authors present an infant with a multisystem phenotype where the intestinal manifestations were as life limiting as the central nervous system features. Severe chronic diarrhea resulted in failure to thrive, dehydration, electrolyte derangements, long-term hospit...

Strict regulation of stem cell metabolism is essential for tissue functions and tumor suppression. In this study, we investigated the role of fumarate hydratase (Fh1), a key component of the mitochondrial tricarboxylic acid (TCA) cycle and cytosolic fumarate metabolism, in normal and leukemic hematopoiesis. Hematopoiesis-specific Fh1 deletion (resu...