Type 1 interferonopathy presenting as juvenile idiopathic arthritis with interstitial lung disease: report of a new phenotype.

BACKGROUND: STING-associated vasculopathy with onset in infancy (SAVI) is a type 1 interferonopathy manifesting as a pulmonary and vascular syndrome resulting from gain-of-function mutations in TMEM173, the gene encoding STING. Familial reports in the literature are sparse. CASE PRESENTATION: We report a case series of SAVI in a three generation kindred, with a phenotype of interstitial lung disease (ILD) and rheumatoid factor positive polyarticular juvenile idiopathic arthritis (JIA). Current and historical medical records were reviewed for clinical and laboratory information. Whole blood from cases 1 and 2, plus stored appendicectomy tissue from case 3, underwent DNA sequencing of the TMEM173 gene. Peripheral blood RNA was obtained from cases 1 and 2 for functional assessment of the TMEM173 mutation. DNA sequencing identified the same heterozygous TMEM173 mutation (c.463G > A; p.Val155Met) in all three cases, consistent with a diagnosis of the autosomal dominant condition SAVI. Functional assessment of this mutation identified a prominent interferon signature which was confirmed on repeat testing. CONCLUSIONS: SAVI presented in this family as ILD with early onset juvenile rheumatoid arthritis. This condition should be considered in all rheumatoid arthritis patients with early-onset ILD and in all JIA patients with ILD.

[Familial chilblain lupus: Four cases spanning three generations]. / Lupus-engelures familial : quatre cas sur trois générations.

BACKGROUND: Familial chilblain lupus is a hereditary form of cutaneous lupus erythematosus seen in young children. It shows autosomal dominant inheritance due to mutations in the TREX-1 gene, or, more rarely, SAMHD1 or TMEM173 (STING). It belongs to the type I interferonopathies, i.e. inflammatory diseases associated with excessive interferon production and characterized by a positive "interferon signature". This is a rare entity with fewer than 10 families described to date. We report a new family followed over several years. PATIENTS AND METHODS: The patients were four subjects from the same family and spanning three generations (a brother and sister aged 17 and 15 years, their 39-year-old mother, and their 60-year-old grandfather). The initial cutaneous lesions on the extremities were described as papular, erythematous, purplish, infiltrated, hyperkeratotic, pruritic and/or painful. They occurred in childhood, improved during summer and stabilized over time. Immunological abnormalities such as positive antinuclear antibodies were noted. The interferon signature was positive in all patients. Molecular analysis of TREX-1, SAMHD1 and STING genes in both children showed no evidence of mutation. DISCUSSION: The cutaneous involvement was classic except for absence of the scarring and mutilating progression, photosensitivity and vasculopathy reported in other families. There was no intrafamily variability other than unconstant immunological abnormalities. At the molecular level, no mutations in the known genes were identified. A complementary molecular analysis is in progress. CONCLUSION: We report a new case of familial LEF, thus adding to knowledge about this very rare form of lupus erythematosus.

Comprehensive molecular screening strategy of OCLN in band-like calcification with simplified gyration and polymicrogyria.

Occludin (OCLN) is an important component of the tight junction complex, providing apical intercellular connections between adjacent cells in endothelial and epithelial tissue. In 2010 O'Driscoll et al reported mutations in OCLN to cause band-like calcification with simplified gyration and polymicrogyria (BLC-PMG). BLC-PMG is a rare autosomal recessive syndrome, characterized by early onset seizures, progressive microcephaly, severe developmental delay and deep cortical gray matter and basal ganglia calcification with symmetrical, predominantly fronto-parietal, polymicrogyria. Here we report 4 additional cases of BLC-PMG with novel OCLN mutations, and provide a summary of the published mutational spectrum. More generally, we describe a comprehensive molecular screening strategy taking into account the technical challenges associated with the genetic architecture of OCLN, which include the presence of a pseudo-gene and copy number variants.

ADA2 deficiency: case report of a new phenotype and novel mutation in two sisters.

The objective of this paper is to: describe the phenotype compound heterozygote for mutations in CECR1 in two children. We describe the clinical and immunological phenotype, including the assessment of ADA2 activity, cytokine expression, interferon-stimulated and neutrophil-stimulated gene signatures, and the results of CECR1 sequencing. The first patient presented with intermittent fever, cutaneous vasculitis, myalgia and muscle inflammation on MRI leading to a provisional diagnosis of periarteritis nodosa. Subsequently, two cerebral lacunar lesions were identified following a brain stroke. Clinical features improved on anti-tumour necrosis factor therapy. The first patient's sister demonstrated early-onset, long-lasting anaemia with mild biological inflammation; at the ages of 3 and 5 years, she had presented 2 acute, transient neurological events with lacunar lesions on MRI. CECR1 sequencing identified both sisters to be compound heterozygous for a p.Tyr453Cys mutation and a previously undescribed deletion of exon 7. ADA2 activity was reduced by 50%. Neutrophil-stimulated genes were not overexpressed, but interferon-stimulated genes were. The expression of a panel of other cytokine transcripts was not significantly altered. In conclusion, searching for CECR1 mutation or assessing ADA2 activity should be considered in patients with an atypical presentation of inflammatory disease.

[Type I interferonopathies]. / Interféronopathies de type I.

Type I interferonopathies are a group of Mendelian disorders characterized by a common physiopathology: the up-regulation of type I interferons. To date, interferonopathies include Aicardi-Goutières syndrome, familial chilblain lupus, spondyenchondromatosis, PRoteasome-associated auto-inflammatory syndrome (PRAAS) and Singleton-Merten syndrome. These diseases present phenotypic overlap including cutaneous features like chilblain lupus, that can be inaugural or present within the first months of life. This novel set of inborn errors of immunity is evolving rapidly, with recognition of new diseases and genes. Recent and improved understanding of the physiopathology of overexpression of type I interferons has allowed the development of targeted therapies, currently being evaluated, like Janus-kinases or reverse transcriptase inhibitors.

Unusual cutaneous features associated with a heterozygous gain-of-function mutation in IFIH1: overlap between Aicardi-Goutières and Singleton-Merten syndromes.

Cutaneous lesions described as chilblain lupus occur in the context of familial chilblain lupus or Aicardi-Goutières syndrome. To date, seven genes related to Aicardi-Goutières syndrome have been described. The most recently described encodes the cytosolic double-stranded RNA receptor IFIH1 (also known as MDA5), a key component of the antiviral type I interferon-mediated innate immune response. Enhanced type I interferon signalling secondary to gain-of-function mutations in IFIH1 can result in a range of neuroinflammatory phenotypes including classical Aicardi-Goutières syndrome. It is of note that none of the patients with a neurological phenotype so far described with mutations in this gene was reported to demonstrate cutaneous involvement. We present a family segregating a heterozygous pathogenic mutation in IFIH1 showing dermatological involvement as a prominent feature, variably associated with neurological disturbance and premature tooth loss. All three affected individuals exhibited increased expression of interferon-stimulated genes in whole blood, and the mutant protein resulted in enhanced interferon signalling in vitro, both in the basal state and following ligand stimulation. Our results further extend the phenotypic spectrum associated with mutations in IFIH1, indicating that the disease can be confined predominantly to the skin, while also highlighting phenotypic overlap with both Aicardi-Goutières syndrome and Singleton-Merten syndrome.

Therapies in Aicardi-Goutières syndrome.

Aicardi-Goutières syndrome (AGS) is a genetically determined disorder, affecting most particularly the brain and the skin, characterized by the inappropriate induction of a type I interferon-mediated immune response. In most, but not all, cases the condition is severe, with a high associated morbidity and mortality. A number of important recent advances have helped to elucidate the biology of the AGS-related proteins, thus providing considerable insight into disease pathology. In this study, we outline the clinical phenotype of AGS, paying particular attention to factors relevant to therapeutic intervention. We then discuss the pathogenesis of AGS from a molecular and cell biology perspective. Finally, we suggest possible treatment strategies in light of these emerging insights.

Systemic lupus erythematosus due to C1q deficiency with progressive encephalopathy, intracranial calcification and acquired moyamoya cerebral vasculopathy.

We report a female with infantile onset of systemic lupus erythematosus secondary to C1q deficiency, in whom we identified a novel homozygous mutation in C1qB. The patient developed a progressive encephalopathy associated with spasticity, and suffered several arterial ischaemic strokes. Cerebral imaging demonstrated acquired intracranial calcification and a cerebral vasculopathy reminiscent of moyamoya. This case demonstrates overlap with some features of Aicardi-Goutières syndrome which, like C1q deficiency, is a monogenic cause of inflammation involving dysregulation of the innate immune system and stimulation of a type I interferon response.

[Genetic syndromes that mimic congenital infections: report of 2 cases]. / Syndromes génétiques mimant les infections congénitales : à propos de 2 cas.

Genetic syndromes that mimic congenital infections must be recognized because of the associated risk of recurrence. We describe a male infant who was born with the association of intra-uterine growth retardation, microcephaly, intracranial calcifications, white matter abnormalities, microphtalmy, bilateral cataract, and hearing loss. Congenital cytomegalovirus (CMV) infection was suspected, but serologic CMV markers were not decisive (IgG+/IgM-). His half-sister (same father) presented a similar phenotype. Therefore, the diagnosis of congenital CMV infection was questioned and a genetic hypothesis was suggested. In 1983, Baraitser et al. first described two brothers with microcephaly and intracranial calcifications and negative TORCH analysis. Later, a number of authors reported children in whom detailed investigation failed to objectively confirm an intra-uterine infective agent. Clinical features include severe postnatal microcephaly, seizures, and pronounced developmental arrest. These cases have been considered to define a distinct autosomal recessive disorder first named pseudo-Torch syndrome. The family described herein is different from the cases previously described with a suspected autosomal dominant inheritance, severe ophtalmological abnormalities, and unusual brain imaging.

Treatment of Gastrointestinal Bleeding in a Probable Case of Cerebroretinal Microangiopathy with Calcifications and Cysts.

Cerebroretinal microangiopathy with calcifications and cysts (CRMCC) is a highly pleiotropic disorder, particularly affecting the eye, brain, bone, and gut. The potential catastrophic sequelae of the associated gastrointestinal phenotype, variably characterised by both chronic bleeding and liver failure, is becoming increasingly apparent. Here we report a probable case of CRMCC with pre- and postnatal growth restriction, bilateral exudative retinopathy, a pathognomonic pattern of intracranial calcification, white matter disease, osteopenia with a tendency to fractures, and chronic gastrointestinal bleeding secondary to abnormal dilated vasculature. The gastrointestinal endoscopic findings were characteristic of gastric antral vascular ectasia (GAVE). Treatment with a combination of oral oestrogen and progesterone ameliorated the gastrointestinal blood loss such that monthly blood transfusions could be stopped. The benefit of this relatively benign therapy in managing the potentially life-limiting consequences of an abnormal gastrointestinal vasculature in CRMCC is of great interest.

Chilblains as a diagnostic sign of aicardi-goutières syndrome.

Aicardi-Goutières syndrome (AGS) is a genetically heterogeneous disorder showing variability in age of onset and clinical features. Chilblain lesions have been described in AGS patients and recent papers have discussed the clinical, molecular and cutaneous histopathological overlap with chilblain lupus. Here we report on 2 unrelated children with AGS and chilblain lesions, whose clinical histories and examination findings well illustrate the wide phenotypic variability that can be seen in this pleiotropic disorder. Although both patients show remarkable similarity in the histopathology of their associated skin lesions, with thrombi formation, fat necrosis and hyalinization of the subcutaneous tissue, we note that the histopathology reported in other AGS cases with chilblains does not necessarily demonstrate this same uniformity. Our findings highlight the significant role of the characteristic chilblain skin lesions in the diagnosis of AGS, and variability in the associated histopathology which may relate to the stage and severity of the disease.

Aicardi-Goutières syndrome presenting with haematemesis in infancy.

UNLABELLED: Aicardi-Goutières syndrome is a genetic childhood encephalopathy characterized by basal ganglia calcification, chronic cerebrospinal lymphocytosis and elevated cerebrospinal fluid interferon-alpha, mimicking acquired congenital viral infections. As more is discovered about the pathogenesis of Aicardi-Goutières, it is becoming evident that a dysfunction of the immune system is likely to be responsible for the disease phenotype. We describe a previously healthy 2-month-old female infant who presented with haematemesis and seizures and was subsequently diagnosed with Aicardi-Goutières syndrome. To our knowledge, this is the first documented case of Aicardi-Goutières syndrome presenting with haematemesis. The gastrointestinal tract is an area of high cell loss, revealing early signs of systemic inflammation and we postulate that a systemic proinflammatory milieu occurs in Aicardi-Goutières syndrome. CONCLUSION: Aicardi-Goutières syndrome can present with haematemesis, adding to the growing evidence that the Aicardi-Goutières syndrome spectrum encompasses an immune-mediated multisystem involvement. Gastrointestinal inflammation should also be considered in these patients and treated appropriately.

Aicardi-Goutieres syndrome: neuroradiologic findings and follow-up.

BACKGROUND AND PURPOSE: To date, few studies have focused specifically on imaging findings in Aicardi-Goutières syndrome (AGS). We set out to evaluate retrospectively neuroradiologic data from a large sample of patients with AGS, focusing on the pattern of white matter abnormalities and the temporal evolution of the cerebral involvement to establish the radiologic natural history of the disease. MATERIALS AND METHODS: Thirty-six patients, 18 girls and 18 boys, were included. All had a clinical diagnosis of AGS, genetically confirmed in 31 of them. For every subject, we reviewed at least 1 CT and 1 MR imaging study; 19 (52.7%) had multiple examinations. In all, we reviewed 109 examinations. Clinical-neuroradiologic comparisons were analyzed by using the chi(2) test. RESULTS: Calcifications were found in all subjects, mainly in the basal ganglia, lobar white matter, and dentate nuclei. Abnormal white matter was present in all the subjects, showing 2 patterns of distribution: diffuse in 18 (50%) and an anteroposterior gradient in 18 (50%). Cystic areas were observed in the temporal and/or frontal lobes in 12/36 patients (33.3%). A correlation was found between early age at onset and severity of the leukoencephalopathy in the frontal (P = .024) and temporal (P = .034) regions. A significant degree of cerebral atrophy was found in 31/36 subjects (86.1%). The neuroradiologic presentation remained substantially stable with time. CONCLUSIONS: The different neuroradiologic presentations of AGS are here outlined for the first time in a large sample of patients. These findings may facilitate more precise and earlier diagnosis of this rare but probably underdiagnosed syndrome.

Band-like intracranial calcification with simplified gyration and polymicrogyria: a distinct "pseudo-TORCH" phenotype.

The combination of intracranial calcification and polymicrogyria is usually seen in the context of intrauterine infection, most frequently due to cytomegalovirus. Rare familial occurrences have been reported. We describe five patients-two male-female sibling pairs, one pair born to consanguineous parents, and an unrelated female-with a distinct pattern of band-like intracranial calcification associated with simplified gyration and polymicrogyria. Clinical features include severe post-natal microcephaly, seizures and profound developmental arrest. Testing for infectious agents was negative. We consider that these children have the same recognizable "pseudo-TORCH" phenotype inherited as an autosomal recessive trait.

Two further cases of spondyloenchondrodysplasia (SPENCD) with immune dysregulation.

Although the diagnosis of spondyloenchondrodysplasia (SPENCD) can only be made in the presence of characteristic metaphyseal and vertebral lesions, a recent report has highlighted the pleiotropic manifestations of this disorder which include significant neurological involvement and variable immune dysfunction. Here we present two patients, one of whom was born to consanguineous parents, further illustrating the remarkable clinical spectrum of this disease. Although both patients demonstrated intracranial calcification, they were discordant for the presence of mental retardation, spasticity and white matter abnormalities. And whilst one patient had features consistent with diagnoses of Sjögren syndrome, polymyositis, hypothyroidism and severe scleroderma, the other patient had clinical manifestations and an autoantibody profile of systemic lupus erythematosus. These cases further illustrate the association of SPENCD with immune dysregulation and highlight the differential diagnosis with Aicardi-Goutières syndrome and other disorders associated with the presence of intracranial calcification. Undoubtedly, identification of the underlying molecular and pathological basis of SPENCD will provide important insights into immune and skeletal regulation.

The neonatal form of Aicardi-Goutières syndrome masquerading as congenital infection.

Aicardi-Goutières syndrome (AGS) is a rare, genetically-determined encephalopathy whose importance from a neonatology perspective is magnified because of the risk of misdiagnosis as the sequelae of congenital infection. Molecular advances have shown that AGS can be caused by mutations in any one of at least five genes (four of which have been identified). A recent genotype-phenotype study has shown that a neonatal form of the disease, highly reminiscent of congenital infection, is seen particularly with TREX1 mutations. It seems likely that the enzymes defective in AGS are involved in digesting endogenous nucleic acids (DNA and RNA) produced during normal cell replication, and that a failure of this removal results in inappropriate triggering of the innate immune system. This hypothesis explains the remarkable phenotypic overlap of AGS with congenital infection, where a similar interferon alpha mediated innate immune response is triggered by viral, as opposed to self, nucleic acids.

Cerebroretinal microangiopathy with calcifications and cysts (CRMCC).

Extensive intracranial calcifications and leukoencephalopathy are seen in both Coats plus and leukoencephalopathy with calcifications and cysts (LCC; Labrune syndrome). Coats plus syndrome is additionally characterized by the presence of bilateral retinal telangiectasia and exudates while LCC shows the progressive formation of parenchymal brain cysts. Despite these apparently distinguishing features, recent evidence suggests that Coats plus and LCC represent the same clinical entity with a common primary pathogenesis involving a small vessel obliterative microangiopathy. Here, we describe eight previously unreported cases, and present an update on one of the original Coats plus patients to highlight the emerging core clinical features of the "cerebroretinal microangiopathy with calcification and cysts" (CRMCC) phenotype.

Aicardi-Goutières syndrome presenting atypically as a sub-acute leukoencephalopathy.

Aicardi-Goutières syndrome is an autosomal recessive encephalopathy characterised by acquired microcephaly, basal ganglia calcifications, leukodystrophy, cerebral atrophy, chronic cerebrospinal lymphocytosis, and raised titres of interferon alpha in the cerebrospinal fluid. The disease onset is generally within the first months of life. We here report a case of Aicardi-Goutières syndrome presenting atypically as a sub-acute leukoencephalopathy following satisfactory psychomotor development up to the age of 16 months. This case highlights the importance of considering Aicardi-Goutières syndrome in the differential diagnosis of an unexplained leukoencephalopathy and the possibility of later onset of the disease.

Variable phenotype including Leigh syndrome with a 9185T>C mutation in the MTATP6 gene.

We describe 15 members of a Caucasian family with an apparently homoplasmic T-->C mutation at nucleotide position 9185 (9185T>C) in the mtDNA encoded MTATP6 (ATPase 6) gene. The clinical phenotype is extremely variable and includes late-onset Leigh syndrome (LS), isolated demyelinating peripheral neuropathy and neurogenic muscle weakness, ataxia and retinitis pigmentosa (NARP). Following recent reports of this same mutation in a single case and in a family with late-onset LS and NARP-like features, our paper emphasises the role of MTATP6 in LS and expands the associated clinical phenotype further.

Severe childhood SMA and axonal CMT due to anticodon binding domain mutations in the GARS gene.

We screened 100 patients with inherited and sporadic lower motor neuron degeneration and identified three novel missense mutations in the glycyl-tRNA synthetase (GARS) gene. One mutation was in the anticodon binding domain and associated with onset in early childhood and predominant involvement of the lower limbs, thus extending the phenotype associated with GARS mutations.