CNS demyelination associated with immune dysregulation and a novel CTLA-4 variant.

BACKGROUND: The cytotoxic T-lymphocyte antigen-4 (CTLA-4) pathway acts as a negative immune regulator of T-cell activation and promotes self-tolerance. CASE: We report the first case of biopsy-proven central nervous system inflammatory demyelination in the context of primary immunodeficiency and a novel CTLA-4 variant. CONCLUSION: This case has significant implications for the development of novel treatments for autoimmune conditions including multiple sclerosis and further emphasises the need for caution with clinical use of CTLA-4 immune checkpoint inhibitors in those with a history of inflammatory demyelination.

Cerebral autosomal recessive arteriopathy with subcortical infarcts and leukoencephalopathy (CARASIL).

A 44-year-old Caucasian man presented with seizures and cognitive impairment. He had marked retinal drusen, and MR brain scan showed features of cerebral small vessel disease; he was diagnosed with a leukoencephalopathy of uncertain cause. He died at the age of 46 years and postmortem brain examination showed widespread small vessel changes described as a vasculopathy of unknown cause. Seven years postmortem, whole-genome sequencing identified a homozygous nonsense HTRA1 mutation (p.Arg302Ter), giving a retrospective diagnosis of cerebral autosomal recessive arteriopathy with subcortical infarcts and leukoencephalopathy.

Recurrent TTN metatranscript-only c.39974-11T>G splice variant associated with autosomal recessive arthrogryposis multiplex congenita and myopathy.

We present eight families with arthrogryposis multiplex congenita and myopathy bearing a TTN intron 213 extended splice-site variant (NM_001267550.1:c.39974-11T>G), inherited in trans with a second pathogenic TTN variant. Muscle-derived RNA studies of three individuals confirmed mis-splicing induced by the c.39974-11T>G variant; in-frame exon 214 skipping or use of a cryptic 3' splice-site effecting a frameshift. Confounding interpretation of pathogenicity is the absence of exons 213-217 within the described skeletal muscle TTN N2A isoform. However, RNA-sequencing from 365 adult human gastrocnemius samples revealed that 56% specimens predominantly include exons 213-217 in TTN transcripts (inclusion rate ≥66%). Further, RNA-sequencing of five fetal muscle samples confirmed that 4/5 specimens predominantly include exons 213-217 (fifth sample inclusion rate 57%). Contractures improved significantly with age for four individuals, which may be linked to decreased expression of pathogenic fetal transcripts. Our study extends emerging evidence supporting a vital developmental role for TTN isoforms containing metatranscript-only exons.

Inflammatory Myositis Secondary to Anti-Retroviral Therapy in a Child; Case Report and Review of the Literature.

Here, we describe a five year old girl with congenital HIV who had a six-week onset of rapidly deteriorating mobility and progressive proximal muscle weakness, associated with a raised Creatine Kinase (CK) level of 4330 U/L [25-200 U/L], subsequently diagnosed with an inflammatory myositis. Potential causes were investigated by paediatric neurology and immunology teams. Her viral load had been undetectable over the preceding two years, excluding a primary HIV myositis. While MRI scanning did not show evidence of definite myositis, a muscle biopsy showed evidence of an inflammatory process, comprising a moderate endomysial, perimysial and perivascular mononuclear (CD8 + T cell) infiltrate with increased MHC expression. No particular features of dermatomyositis or immune-mediated necrotising myopathy were identified and there were no features of an inclusion body myositis.Given the absence of active HIV infection, the role of anti-retroviral medications was considered. She had had a recent switch in medication, from twice daily Raltegravir (an Integrase Strand Transfer Inhibitor, INSTI) to once daily Dolutegravir (an INSTI) while continuing on an established daily protocol of Abacavir and Lamivudine (Nucleoside Reverse Transcriptase Inhibitors). Changing the Dolutegravir back to Raltegravir, in combination with continuing Lamivudine and Abacavir for two months made no difference to her weakness or CK levels. Moreover, this drug regimen had been well-tolerated over the preceding 19 month period. Changing the anti-retroviral regime completely to a single drug class (Protease Inhibitors) of Ritonavir and Darunavir, resulted in a dramatic improvement in her symptomatology. Within ten days she regained the ability to stand and walk, with a reduction in her CK from 1700 U/L at time of switch to 403 U/L [25-200]. This case highlights the potential risk of developing inflammatory myositis from anti-retrovirals even 19 months into treatment.

Slow-Growing Pituitary Metastasis from Renal Cell Carcinoma: Literature Review.

BACKGROUND: Tumor metastasis to the pituitary is rare, most commonly reported with either breast or lung cancer metastasizing to the neurohypophysis. Pituitary metastases of renal cell carcinoma (RCC) are by contrast infrequently described even within this scarce literature. We present an illustrative case of RCC pituitary metastasis 15 years after radical nephrectomy for primary disease and a review of the published literature. CASE DESCRIPTION: A 69-year-old female was diagnosed with a large sellar mass with suprasellar extension. The initial radiologic diagnosis was most in keeping with pituitary macroadenoma, although prominent vascular flow voids were noted. Endoscopic endonasal transsphenoidal adenectomy was challenging on account of significant intraoperative hemorrhage from an unusually vascular tumor. Pathologic examination supported a diagnosis of metastatic clear cell renal carcinoma. Literature review identified 41 cases of RCC pituitary metastasis since 1984. The mean age at time of diagnosis with pituitary metastasis was 59.5 years (range 35-81 years, 73% male). Pituitary metastasis was the initial presentation of RCC in 10 patients. The median time from RCC diagnosis to pituitary metastasis was 1 year (range 0-27 years). Surgical resection was performed for 30 patients, of which 47% reported a highly vascular tumor. CONCLUSIONS: We highlight the potential for delayed metastasis to the pituitary to masquerade as a macroadenoma. Imaging consistent with rich vascularity should bring the diagnosis of RCC metastasis into the differential and is important to note when planning surgical resection in such cases.

A rare case of adult onset LPIN1 associated rhabdomyolysis.

Pathogenic variants in LPIN1 are a recognised cause of severe and often fatal rhabdomyolysis in childhood. We present a rare case of adult onset recurrent rhabdomyolysis due to compound heterozygous variants in LPIN1. Despite first presenting with rhabdomyolysis in his twenties and having undergone extensive investigations, the patient did not receive a diagnosis until he was 46 years of age. DNA sequencing revealed a pathogenic deletion involving exon 18 of LPIN1 in conjunction with a c.2410G>A missense variant in exon 19. Whilst LPIN1 variants are a noteworthy cause of severe recurrent rhabdomyolysis in childhood, this is the first detailed description and only the second reported case of adult onset rhabdomyolysis. Variants in LPIN1 should be considered as a cause of recurrent severe rhabdomyolysis in adults when other more common causes have been excluded.

A novel de novo ACTA1 variant in a patient with nemaline myopathy and mitochondrial Complex I deficiency.

We describe the presentation and follow-up of a three-year-old girl with nemaline myopathy due to a de-novo variant in ACTA1 (encoding skeletal alpha actin) and moderately low enzyme level of Complex I of the mitochondrial respiratory chain. She presented in the neonatal period with hypotonia, followed by weakness in the facial, bulbar, respiratory and neck flexors muscles. A biopsy of her quadriceps muscle at the age of one year showed nemaline rods. Based on her clinical presentation of a congenital myopathy and histopathological features on a muscle biopsy, ACTA1 was sequenced, and this revealed a novel sequence variant, c.760 A>C p. (Asn254His). In addition, mitochondrial respiratory chain enzymatic activity of skeletal muscle biopsy showed a moderately low activity of complex I (nicotinamide adenine dinucleotide (NADH): ubiquinone oxidoreductase). Disturbances of Complex I of the respiratory chain have been reported in patients with nemaline myopathy, although the mechanism remains unclear.