Onset In Early Childhood Research Articles

G.P.216: Allele-specific silencing of a dominant-negative mutation using siRNA or LNA antisense oligonucleotides alleviates the phenotype of a cellular model of Ullrich congenital muscular dystrophy

Congenital muscular dystrophy type Ullrich (UCMD) is a severe progressive disorder of early childhood onset, presenting with generalized muscle weakness, distal joint hypermobility, proximal joint contractures and respiratory failure as the main features. At present, there are no pharmacological treatment options available for children affected with this disease. In the laboratory we aim at exploring targeted RNAi and antisense approaches as potential therapies for UCMD. Dominant and recessive mutations in the three genes coding for collagen type VI (COL6A1, COL6A2, COL6A3) underlie UCMD, with dominant-negative mutations accounting for the majority of cases. Achieving allele-specific silencing of the mutant collagen VI transcript would convert this dominant-negative state into a clinically asymptomatic haploinsufficient state. We have previously demonstrated the allele-specificity and efficiency of siRNA oligos to downregulate the expression of a mutant COL6A3 transcript in vitro. We have now extended our study to Locked Nucleic Acid (LNA)-containing antisense oligonucleotides, which are short, stable, and RNaseH-competent oligonucleotides that can be delivered without any carrier. We used outcome measures such as unsaturated PCR, quantitative RT-PCR and immunoblot on treated cell lysates, and confocal microscopy on treated fixed cells, and found that both RNAi and RNase-H pathways were comparably effective. This study provides further insights into the comparative allele-specificity of these two pathways to target dominant mutations at the transcript level, with the goal of developing optimal compounds for in vivo application.

Loss of Raf-1 kinase inhibitory protein delays early-onset severe retinal ciliopathy in Cep290rd16 mouse.

Mutations in the cilia-centrosomal protein of centrosomal protein of 290 kDa (CEP290) result in severe ciliopathies, including autosomal recessive early onset childhood blindness disorder Leber congenital amaurosis (LCA). The Cep290(rd16) (retinal degeneration 16) mouse model of CEP290-LCA exhibits accumulation of CEP290-interacting protein Raf-1 kinase inhibitory protein (RKIP) prior to onset of retinal degeneration (by postnatal day P14). We hypothesized that reducing RKIP levels in the Cep290(rd16) mouse will delay or improve retinal phenotype. We generated double mutant mice by combining the Cep290(rd16) and Rkip(ko) alleles (Cep290(rd16):Rkip(+/ko) and Cep290(rd16):Rkip(ko/ko)). Retinal function was assessed by ERG and retinal morphology and protein trafficking were assessed by histology, transmission electron microscopy (TEM), and immunofluorescence analysis. Cell death was examined by apoptosis. Prior to testing our hypothesis, we examined ERG and retinal morphology of Rkip(ko/ko) mice and did not find any detectable differences compared with wild-type mice. The Cep290(rd16):Rkip(+/ko) mice exhibited similar retinopathy as Cep290(rd16); however, Cep290(rd16): Rkip(ko/ko) double knockout mice demonstrated a substantial improvement (>9-fold) in photoreceptor function and structure at P18 as of Cep290(rd16) mice. We consistently detected transient preservation of photoreceptors at P18 and polarized trafficking of opsins to sensory cilia in the double mutant mice; however, retinal degeneration ensued by P30. Our studies implicate CEP290-RKIP pathway in CEP290-retinal degeneration and suggest that targeting RKIP levels can delay photoreceptor degeneration, assisting in extending the time-window for treating such rapidly progressing blindness disorder.

NPHS2 variation in Chinese southern infants with late steroid-resistant nephrotic syndrome

NPHS2 mutations are responsible for autosomal recessive familial steroid-resistant nephrotic syndrome (SRNS) with minor glomerular abnormalities or focal segmental glomerulosclerosis (FSGS), which is characterized by early childhood onset and rapid progression to chronic renal insufficiency. This gene mutation is also responsible for an adolescent onset form of autosomal recessive familial FSGS with heavy proteinuria. Many infants with late steroid-resistant nephrotic syndrome (late SRNS) are prone to an implicated clinical and therapeutic course. The etiopathogenesis and the long-term prognosis of late SRNS remain obscure. Considering the similar steroid resistance between late and initial SRNS, analysis of NPHS2 variation was performed in 70 sporadic Chinese infants with late SRNS and 70 controls in the present study to investigate the possible role of NPHS2 gene in late SRNS. The variation analysis revealed three polymorphisms (288C > T heterozygous in exon 2, 954T > C heterozygous and homozygous, and 1038A > G heterozygous in exon 8) in 22 out of 70 patients studied. In conclusion, NPHS2 gene mutations are not a major cause of chronic renal insufficiency caused by late SRNS in Chinese southern infants.

Transplantation in inborn errors of metabolism: current considerations and future perspectives.

Inborn errors of metabolism (IEM) comprise an assorted group of inherited diseases, some of which are due to disordered lysosomal or peroxisomal function and some of which might be improved following haemopoietic cell transplantation (HCT). In these disorders, the onset in infancy or early childhood is typically accompanied by rapid deterioration, resulting in early death in the more severe phenotypes. Timely diagnosis and immediate referral to an IEM specialist are essential steps in optimal management. Treatment recommendations are based on the diagnosis, its phenotype, rate of progression, prior extent of disease, family values and expectations and the risks and benefits associated with available therapies, including HCT. International collaborative efforts are of utmost importance in determining outcomes of therapy for these rare diseases, and have improved those outcomes significantly over recent decades. This discussion focuses on HCT in IEM, providing an international perspective on progress, limitations, and future directions.

Research updates in neuroimaging studies of children who stutter.

In the past two decades, neuroimaging investigations of stuttering have led to important discoveries of structural and functional brain differences in people who stutter, providing significant clues to the neurological basis of stuttering. One major limitation, however, has been that most studies so far have only examined adults who stutter, whose brain and behavior likely would have adopted compensatory reactions to their stuttering; these confounding factors have made interpretations of the findings difficult. Developmental stuttering is a neurodevelopmental condition, and like many other neurodevelopmental disorders, stuttering is associated with an early childhood onset of symptoms and greater incidence in males relative to females. More recent studies have begun to examine children who stutter using various neuroimaging techniques that allow examination of functional neuroanatomy and interaction of major brain areas that differentiate children who stutter compared with age-matched controls. In this article, I review these more recent neuroimaging investigations of children who stutter, in the context of what we know about typical brain development, neuroplasticity, and sex differences relevant to speech and language development. Although the picture is still far from complete, these studies have potential to provide information that can be used as early objective markers, or prognostic indicators, for persistent stuttering in the future. Furthermore, these studies are the first steps in finding potential neural targets for novel therapies that may involve modulating neuroplastic growth conducive to developing and maintaining fluent speech, which can be applied to treatment of young children who stutter.

Progressive hearing loss and vestibular dysfunction caused by a homozygous nonsense mutation in CLIC5.

In a consanguineous Turkish family diagnosed with autosomal recessive nonsyndromic hearing impairment (arNSHI), a homozygous region of 47.4 Mb was shared by the two affected siblings on chromosome 6p21.1-q15. This region contains 247 genes including the known deafness gene MYO6. No pathogenic variants were found in MYO6, neither with sequence analysis of the coding region and splice sites nor with mRNA analysis. Subsequent candidate gene evaluation revealed CLIC5 as an excellent candidate gene. The orthologous mouse gene is mutated in the jitterbug mutant that exhibits progressive hearing impairment and vestibular dysfunction. Mutation analysis of CLIC5 revealed a homozygous nonsense mutation c.96T>A (p.(Cys32Ter)) that segregated with the hearing loss. Further analysis of CLIC5 in 213 arNSHI patients from mostly Dutch and Spanish origin did not reveal any additional pathogenic variants. CLIC5 mutations are thus not a common cause of arNSHI in these populations. The hearing loss in the present family had an onset in early childhood and progressed from mild to severe or even profound before the second decade. Impaired hearing is accompanied by vestibular areflexia and in one of the patients with mild renal dysfunction. Although we demonstrate that CLIC5 is expressed in many other human tissues, no additional symptoms were observed in these patients. In conclusion, our results show that CLIC5 is a novel arNSHI gene involved in progressive hearing impairment, vestibular and possibly mild renal dysfunction in a family of Turkish origin.

Syndromes associated with mitochondrial DNA depletion

Mitochondrial dysfunction accounts for a large group of inherited metabolic disorders most of which are due to a dysfunctional mitochondrial respiratory chain (MRC) and, consequently, deficient energy production. MRC function depends on the coordinated expression of both nuclear (nDNA) and mitochondrial (mtDNA) genomes. Thus, mitochondrial diseases can be caused by genetic defects in either the mitochondrial or the nuclear genome, or in the cross-talk between the two. This impaired cross-talk gives rise to so-called nuclear-mitochondrial intergenomic communication disorders, which result in loss or instability of the mitochondrial genome and, in turn, impaired maintenance of qualitative and quantitative mtDNA integrity. In children, most MRC disorders are associated with nuclear gene defects rather than alterations in the mtDNA itself.The mitochondrial DNA depletion syndromes (MDSs) are a clinically heterogeneous group of disorders with an autosomal recessive pattern of transmission that have onset in infancy or early childhood and are characterized by a reduced number of copies of mtDNA in affected tissues and organs. The MDSs can be divided into least four clinical presentations: hepatocerebral, myopathic, encephalomyopathic and neurogastrointestinal. The focus of this review is to offer an overview of these syndromes, listing the clinical phenotypes, together with their relative frequency, mutational spectrum, and possible insights for improving diagnostic strategies.

Feeding Styles and the Body Weight Status of Preschool-aged Children

Early-onset pediatric obesity has become a major health concern in the United States. One of the key contributing factors to early-onset childhood obesity is how children are socialized to the eating and mealtime environment. The purpose of this study was to determine the extent to which maternal feeding styles influenced the child's actual weight. The study used a descriptive correlational research design. Ten pediatric experts classified the authoritative feeding style as healthy. The maternal behavior of the authoritative feeding style was significantly associated with healthy behaviors in the child.

Callous-Unemotional Behavior and Early-Childhood Onset of Behavior Problems: The Role of Parental Harshness and Warmth

Youth with callous-unemotional (CU) behavior are at risk of developing more severe forms of aggressive and antisocial behavior. Previous cross-sectional studies suggest that associations between parenting and conduct problems are less strong when children or adolescents have high levels of CU behavior, implying lower malleability of behavior compared to low-CU children. The current study extends previous findings by examining the moderating role of CU behavior on associations between parenting and behavior problems in a very young sample, both concurrently and longitudinally, and using a variety of measurement methods. Data were collected from a multi-ethnic, high-risk sample at ages 2 to 4 (N = 364; 49% female). Parent-reported CU behavior was assessed at age 3 using a previously validated measure (Hyde et al., 2013). Parental harshness was coded from observations of parent–child interactions and parental warmth was coded from 5-min speech samples. In this large and young sample, CU behavior moderated cross-sectional correlations between parent-reported and observed warmth and child behavior problems. However, in cross-sectional and longitudinal models testing parental harshness, and longitudinal models testing warmth, there was no moderation by CU behavior. The findings are in line with recent literature suggesting parental warmth may be important to child behavior problems at high levels of CU behavior. In general, however, the results of this study contrast with much of the extant literature and suggest that in young children, affective aspects of parenting appear to be related to emerging behavior problems, regardless of the presence of early CU behavior.

Consequences of antibiotics and infections in infancy: bugs, drugs, and wheezing

BackgroundThe prevalence of asthma has increased alarmingly in the past 2 to 3 decades. Increased antibiotic use in infancy has been suggested to limit exposure to gastrointestinal microbes and to predispose to asthma in later life. ObjectiveTo evaluate the association between antibiotic exposure during the first year of life and the development of asthma up to the age of 7 years. MethodsA retrospective population-based study of a cohort of children enrolled in a nationwide employer-provided health insurance plan from January 1, 1999, through December 31, 2006, in the United States (n = 62,576). We evaluated the association between antibiotic exposure during the first year of life and subsequent development of 3 asthma phenotypes: transient wheezing (began and resolved before 3 years of age), late-onset asthma (began after 3 years of age), and persistent asthma (began before 3 years of age and persisted through 4-7 years of age). ResultsAntibiotic use in the first year of life was associated with the development of transient wheezing (odds ratio [OR], 2.0; 95% confidence interval [CI], 1.9-2.2; P < .001) and persistent asthma (OR, 1.6; 95% CI, 1.5-1.7; P < .001). A dose-response effect was observed. When 5 or more antibiotic courses were received, the odds of persistent asthma doubled (OR, 1.9; 95% CI, 1.5-2.6; P < .001). There is no association between antibiotic use and late-onset asthma. ConclusionAntibiotic use in the first year life is associated with an increased risk of early-onset childhood asthma that began before 3 years of age. The apparent effect has a clear dose response. Heightened caution about avoiding unnecessary use of antibiotics in infants is warranted.

Late diagnosis of fucosidosis in a child with progressive fixed dystonia, bilateral pallidal lesions and red spots on the skin

Fucosidosis is a rare lysosomal storage disease. A 14-year-old girl is presented, with recurrent infections, progressive dystonic movement disorder and mental retardation with onset in early childhood. The clinical picture was also marked by mild morphologic features, but absent dysostosis multiplex and organomegaly. MRI images at 6.5 years of age were reminiscent of pallidal iron deposition (“eye-of-the-tiger” sign) seen in neurodegeneration with brain iron accumulation (NBIA) disorders. Progressively spreading angiokeratoma corporis diffusum led to the correct diagnosis. This case extends the scope of clinical and neuroradiological manifestations of fucosidosis.

Glutamatergic candidate genes in autism spectrum disorder: an overview

Autism spectrum disorders (ASD) are neurodevelopmental disorders with early onset in childhood. Most of the risk for ASD can be explained by genetic variants that act in interaction with biological environmental risk factors. However, the architecture of the genetic components is still unclear. Genetic studies and subsequent systems biological approaches described converging functional effects of identified genes towards pathways relevant for neuronal signalling. Mouse models suggest an aberrant synaptic plasticity at the neuropathological level, which is believed to be conferred by dysregulation of long-term potentiation or depression of neuronal connections. A central pathway regulating these mechanisms is glutamatergic signalling. Here, we hypothesized that susceptibility genes for ASD are enriched for components of this pathway. To further understand the impact of ASD risk genes on the glutamatergic pathway, we performed a systematic review using the literature database "pubmed" and the "AutismKB" knowledgebase. We provide an overview of the glutamatergic system in typical brain function and development, and summarize findings from linkage, association, copy number variants, and sequencing studies in ASD to provide a comprehensive picture of the glutamatergic landscape of ASD genetics. Genetic variants associated with ASD were enriched in glutamatergic pathways, affecting receptor signalling, metabolism and transport. Furthermore, in genetically modified mouse models for ASD, pharmacological compounds acting on ionotropic or metabotropic receptor activity are able to rescue ASD reminscent phenotypes. We conclude that glutamatergic genetic risk factors for ASD show a complex pattern and further studies are needed to fully understand its mechanisms, before translation of findings into clinical applications and individualized treatment approaches will be possible.

Evaluation of bone infiltration of skull base in Gaucher disease

formed nodules, giving a pattern of cirrhosis with prominent microvesicular lipid deposition, and enlarged foamy macrophages. A sixth biopsy was obtained at age 24 years, when AST and ALT were 115 U/L and 136 U/L, respectively. The biopsy showed portal tract fibrous expansion, bridging fibrosis and very focal isolated islands of entrapped hepatic parenchyma and resultant nodule formation (micronodular cirrhosis). Parenchymal hepatocytes had extensive microvesicular steatosis, ceroid laden foamy macrophages without bile duct proliferation. This series of six liver biopsies illustrates the early childhood onset and progressive nature of liver disease in a CESD patient, despite simvastatin use. The depictions of six liver biopsies spanning over two decades may facilitate histopathologic recognition of this underrecognized lysosomal disease, which is crucial since enzyme replacement therapy is available in clinical trials.

Humoral Immune Mechanism of Liver Injury in Giant Cell Hepatitis With Autoimmune Hemolytic Anemia

Giant cell hepatitis with autoimmune hemolytic anemia (GCH-AHA) is presumed to be an autoimmune disease, but the mechanism of liver injury is unknown. We proposed that in CGH-AHA, the humoral limb of autoimmunity is the dominant force driving progressive liver injury. We studied 6 cases of GCH-AHA and 6 cases of autoimmune hepatitis (AIH) with early childhood onset (3 type 1 and 3 type 2). Liver biopsies were graded for portal and periportal inflammation and for giant cells. Immunohistochemistry characterized cellular inflammation and complement involvement in injury by showing C5b-9 complex in hepatocytes. Clinical and biochemical features at presentation were generally similar; however, the absence of autoantibodies and the presence of Coombs positivity did distinguish GCH-AHA from early-onset AIH. Liver biopsy pathology in CGH-AHA showed giant cells and little inflammation, whereas AIH showed the opposite. C5b-9 staining showed high-grade complement-mediated pan-lobular hepatocyte injury in all of the cases with GCH-AHA, whereas little C5b-9 was seen in hepatocytes in cases with AIH. Inflammation in GCH-AHA comprised mainly lobular macrophages and neutrophils, whereas portal and periportal T-cell and B-cell inflammation characterized cases with AIH. Most cases with AIH responded to therapy with prednisone and azathioprine, whereas most cases with GCH-AHA responded only to rituximab. Widespread complement-mediated hepatocyte injury and typical C3a and C5a complement-driven liver inflammation along with Coombs-positive hemolytic anemia in GCH-AHA provide convincing evidence that systemic B-cell autoimmunity plays a central pathologic mechanism in the disease. Our findings support B-cell-directed immunotherapy as a first-line treatment of GCH-AHA.

SiRNA-mediated Allele-specific Silencing of a COL6A3 Mutation in a Cellular Model of Dominant Ullrich Muscular Dystrophy

Congenital muscular dystrophy type Ullrich (UCMD) is a severe disorder of early childhood onset for which currently there is no effective treatment. UCMD commonly is caused by dominant-negative mutations in the genes coding for collagen type VI, a major microfibrillar component of the extracellular matrix surrounding the muscle fibers. To explore RNA interference (RNAi) as a potential therapy for UCMD, we designed a series of small interfering RNA (siRNA) oligos that specifically target the most common mutations resulting in skipping of exon 16 in the COL6A3 gene and tested them in UCMD-derived dermal fibroblasts. Transcript analysis by semiquantitative and quantitative reverse transcriptase PCR showed that two of these siRNAs were the most allele-specific, i.e., they efficiently knocked down the expression from the mutant allele, without affecting the normal allele. In HEK293T cells, these siRNAs selectively suppressed protein expression from a reporter construct carrying the mutation, with no or minimal suppression of the wild-type (WT) construct, suggesting that collagen VI protein levels are as also reduced in an allele-specific manner. Furthermore, we found that treating UCMD fibroblasts with these siRNAs considerably improved the quantity and quality of the collagen VI matrix, as assessed by confocal microscopy. Our current study establishes RNAi as a promising molecular approach for treating dominant COL6-related dystrophies.

Epilepsy-Associated Point Mutation in the Pore Domain of Kv2.1

A large scale sequencing endeavor (Epi4K Consortium, Nature 501:217-221, 2013) recently reported discovery of several de novo mutations in genes encoding ion channels, neurotransmitter receptors and other proteins that may explain severe, early onset childhood epilepsy. One intriguing variant was found in KCNB1, encoding KV2.1. Although KV2.1 is a potassium channel involved in repolarization of neuronal action potentials, it has not previously been associated with epilepsy. The reported variant (T374I) was heterozygous and affects a highly conserved residue within the KV2.1 ion selectivity filter 5 amino acids N-terminal to the GYG motif. We performed heterologous expression of wildtype (WT) and mutant KV2.1 channels and used whole-cell patch clamp recording to define the functional consequences of the mutation and to infer the pathophysiology of the epilepsy. Wild-type or mutant KV2.1 channels were transiently expressed under control of the CMV promoter in CHO cells. Expression of channel subunits was confirmed by co-expression of a fluorescent protein encoded by the same plasmid. Cells expressing homomeric WT-KV2.1 exhibited large outward currents with rapid voltage-dependent activation and slow inactivation. By contrast, cells expressing homomeric KV2.1-T374I exhibited no outward or inward current. Our findings suggest that this mutation impairs ion permeation and confers a loss-of-function as the molecular basis for epilepsy. Further studies will evaluate the impact of mutant subunits on formation of functional heteromultimeric channels to explore possible dominant-negative behavior.

Clinical features, developmental course, and psychiatric comorbidity of adult autism spectrum disorders

Autism spectrum disorders (ASDs) include a heterogeneous group of neurodevelopmental disorders with early onset in childhood. ASDs should be considered lifelong clinical entities, although there is a certain variability in developmental trajectories, and therefore should be considered of great interest also for adulthood psychiatrists. A few studies have been carried out to explore the clinical picture and course development of these disorders during adulthood, or their relationship with other mental disorders. Indeed, ASDs often share overlapping features with other disorders, such as schizophrenia and obsessive-compulsive, mood, and personality disorders, and as a result misdiagnoses often occur. The aim of this review is to summarize the available literature on ASDs in adulthood with a specific focus on the clinical picture, course, and psychiatric comorbidity. It is proposed that a careful diagnostic screening for ASDs in adults would contribute to clarifying the relationship with comorbid psychiatric disorders, while improving the possibility of treatment and outcome of such conditions.

Porokeratosis of Mibelli - literature review and a case report

Porokeratosis is a disorder of epidermal keratinization characterized by annular plaques with an atrophic center and hyperkeratotic edges, and includes a heterogeneous group of disorders that are mostly inherited in an autosomal dominant form. This report describes a 5 year-old female patient, with porokeratosis of Mibelli confirmed histopathologically. The rarity of this disorder, its clinical exuberance and the destructive character of the lesions, as well as the facial and mucosal involvements, unusual in this form of porokeratosis, and also its onset in early childhood motivated this report.

Novel GCH-1 mutations and unusual long-lasting dyskinesias in Korean families with dopa-responsive dystonia

ObjectiveTo describe the long-term follow-up data of Korean patients with GTP cyclohydrolase (GTPCH) I deficient dopa-responsive dystonia (DRD) with novel mutations and unusual long-lasting dyskinesias. MethodsClinical features and genetic testing results of GCH1 from 19 patients that included 4 families who have been followed-up for up to 25 years were analyzed. ResultsGCH1 mutations were confirmed in all our symptomatic subjects including 3 novel point mutations. All the subjects except for one family had typical manifestations of autosomal dominant GTPCH-I deficient DRD including early childhood onset dystonia predominantly in the legs, marked diurnal variation, intact cognition, no other systemic symptoms, and excellent sustained response to levodopa. The one family who was the exception had two gene positive members of DRD and one with dopa-unresponsive cervical dystonia with negative GCH1 mutation. One family and a sporadic case had been reported as gene negative in a previous study, but they typically had preserved dopamine transporter binding and low neopterin levels in cerebrospinal fluids; thus, GCH-1 mutation had been highly suspected, which was now confirmed by repeating the genetic testing this time. An early childhood-onset patient developed choreiform dyskinesias right after administration of levodopa. The dyskinesia had lasted for more than 4 years regardless of the levodopa dosages and then subsided while maintaining levodopa. ConclusionThis report emphasizes the usefulness of the neopterin level in cerebrospinal fluids and dopamine transporter imaging in the differential diagnosis of DRD syndromes and a possible mechanism of levodopa-induced-dyskinesia in early childhood onset case.

P.1.10 siRNA-mediated allele-specific silencing of a dominant negative COL6A3 mutation causing Ullrich Congenital muscular dystrophy

Congenital muscular dystrophy type Ullrich (UCMD) is a severe neuromuscular disorder of early childhood onset, characterized by proximal or generalized muscle weakness, distal joint hypermobility, progressive joint contractures, and skin changes. Progressive scoliosis and diaphragmatic weakness may also develop. At present, there are no pharmacological treatment options available for these patients. Mutations in the three genes coding for collagen type VI are responsible for UCMD, and they are more commonly acting as dominant negative. In this study we further explored the use of RNAi as a potential therapy for dominant UCMD. Achieving allele-specific silencing of the mutant mRNA transcript would convert this dominant-negative state into a clinically asymptomatic haploinsufficient state. We have designed a series of siRNA oligos to target a mutant mRNA transcript lacking the exon 16 of the Collagen VI á3 gene (COL6A3). We tested this series of siRNA in four UCMD-derived dermal fibroblast cells lines. Transcript analysis by semi-quantitative and quantitative RT-PCR showed that a subset of these siRNA significantly reduced the expression of the mutant transcript, without affecting the expression of the normal allele, confirming the potency of the allele-specific knockdown. In HEK293T cells these siRNA oligos selectively suppressed protein expression from a reporter construct carrying the mutation, but not from a wild-type construct, suggesting that the collagen VI protein levels are as significantly reduced in an allele-specific manner. Furthermore, we found that treating UCMD fibroblasts with these siRNA oligos considerably improved the quantity and quality of the collagen VI extracellular matrix in cell culture, as visualized and quantified by confocal microscopy of immunostained collagen VI. Our current study serves as a proof-of-principle and establishes RNAi as a promising molecular approach for treating UCMD caused by dominant negative mutations.