Background:Immunodeficiency in ataxia telangiectasia (A-T) is less severe in patients expressing some mutant or normal ATM kinase activity. We, therefore, determined whether expression of residual ATM kinase activity also protected against tumour development in A-T.Methods:From a total of 296 consecutive genetically confirmed A-T patients from the British Isles and the Netherlands, we identified 66 patients who developed a malignant tumour; 47 lymphoid tumours and 19 non-lymphoid tumours were diagnosed. We determined their ATM mutations, and whether cells from these patients expressed any ATM with residual ATM kinase activity.Results:In childhood, total absence of ATM kinase activity was associated, almost exclusively, with development of lymphoid tumours. There was an overwhelming preponderance of tumours in patients <16 years without kinase activity compared with those with some residual activity, consistent with a substantial protective effect of residual ATM kinase activity against tumour development in childhood. In addition, the presence of eight breast cancers in A-T patients, a 30-fold increased risk, establishes breast cancer as part of the A-T phenotype.Conclusion:Overall, a spectrum of tumour types is associated with A-T, consistent with involvement of ATM in different mechanisms of tumour formation. Tumour type was influenced by ATM allelic heterogeneity, residual ATM kinase activity and age.

Ataxia telangiectasia (A-T) typically presents with early-onset progressive cerebellar ataxia, oculomotor apraxia and later, oculo-cutaneous telangiectasia. Extrapyramidal symptoms, apart from chorea, are rare. In this paper, we report a case of A-T with an atypically mild and slowly progressive disease course. Although by history there was mild gait clumsiness in early childhood, the leading problem was that of dystonia with onset at age 15, in the absence of gross gait imbalance or ocular motor apraxia. Dystonia was generalized and with prominent oromandibular involvement. Unusually, a leash of telangiectasia was present on the posterior pharyngeal wall, while other features frequently associated with A-T were absent.

Amyotrophic lateral sclerosis is a progressive and devastating neurodegenerative disease. Despite decades of clinical trials, effective disease modifying drugs remain scarce. To understand the challenges of trial design and delivery, we performed a systematic review of phase II, phase II/III and phase III amyotrophic lateral sclerosis clinical drug trials on trial registries and PubMed between 2008 and 2019. We identified 125 trials, investigating 76 drugs and recruiting more than 15000 people with amyotrophic lateral sclerosis. 90% of trials used traditional fixed designs. The limitations in understanding of disease biology, outcome measures, resources and barriers to trial participation in a rapidly progressive, disabling and heterogenous disease hindered timely and definitive evaluation of drugs in two-arm trials. Innovative trial designs, especially adaptive platform trials may offer significant efficiency gains to this end. We propose a flexible and scalable multi-arm, multi-stage trial platform where opportunities to participate in a clinical trial can become the default for people with amyotrophic lateral sclerosis.

Ataxia-telangiectasia mutated (ATM) is the gene mutated in the cancer-predisposing disorder ataxia-telangiectasia (A-T). We modeled ATM sequence variants identified in UK A-T patients to determine the stability and kinase activity of the resulting proteins as well as the distribution of these mutations across the coding region. Of 20 missense changes modeled, 10 proteins showed ATM kinase activity and 10 showed none. In the majority of cases the mutant ATM protein was unstable, although this was variable. Reduction in ATM kinase activity can result either from the presence of low levels of unstable mutant protein with relatively normal specific kinase activity or from stable mutant protein with deficient ATM kinase activation. Indeed, ATM mutant proteins without kinase activity toward downstream targets were still able to autophosphorylate on serine 1981, although in a much less efficient manner, suggesting that this was not sufficient for ATM activation. In terms of function, green fluorescent protein (GFP)-tagged kinase inactive ATM proteins could form ionizing radiation (IR)-induced foci (IRIF), at least temporarily, which colocalized with the DNA double-strand break (DSB) marker gammaH2AX. Consistent with this, both kinase active and inactive mutant ATM proteins were able to interfere with phosphorylation of targets by endogenous ATM. Since the majority of missense mutations occurred C-terminal to aa1966, including all 10 mutations with absence of kinase activity, the implication was that mutations N-terminal to this, with exceptions, are less likely to result in loss of kinase activity and therefore, are less likely to be identified in A-T patients.