Clinical presentation and long-term outcomes of infantile hypertrophic cardiomyopathy: a European multicentre study

AIMS

Children presenting with hypertrophic cardiomyopathy (HCM) in infancy are reported to have a poor prognosis, but this heterogeneous group has not been systematically characterized. This study aimed to describe the aetiology, phenotype, and outcomes of infantile HCM in a well-characterized multicentre European cohort.

METHODS AND RESULTS

Of 301 children diagnosed with infantile HCM between 1987 and 2019 presenting to 17 European centres [male n = 187 (62.1%)], underlying aetiology was non-syndromic (n = 138, 45.6%), RASopathy (n = 101, 33.6%), or inborn error of metabolism (IEM) (n = 49, 16.3%). The most common reasons for presentation were symptoms (n = 77, 29.3%), which were more prevalent in those with syndromic disease (n = 62, 61.4%, P < 0.001), and an isolated murmur (n = 75, 28.5%). One hundred and sixty-one (53.5%) had one or more co-morbidities. Genetic testing was performed in 163 (54.2%) patients, with a disease-causing variant identified in 115 (70.6%). Over median follow-up of 4.1 years, 50 (16.6%) underwent one or more surgical interventions; 15 (5.0%) had an arrhythmic event (6 in the first year of life); and 48 (15.9%) died, with an overall 5 year survival of 85%. Predictors of all-cause mortality were an underlying diagnosis of IEM [hazard ratio (HR) 4.4, P = 0.070], cardiac symptoms (HR 3.2, P = 0.005), and impaired left ventricular systolic function (HR 3.0, P = 0.028).

CONCLUSIONS

This large, multicentre study of infantile HCM describes a complex cohort of patients with a diverse phenotypic spectrum and clinical course. Although overall outcomes were poor, this was largely related to underlying aetiology emphasizing the importance of comprehensive aetiological investigations, including genetic testing, in infantile HCM.

Urology residency training in Greece. Results from the first national resident survey

BACKGROUND AND OBJECTIVES

This is the first national survey assessing Greek Urology residency programs. The main objective of this study is to assess the level of confidence and perception of Greek Urology residents regarding their educational program and detect areas of improvement.

MATERIAL AND METHODS

A 51-question survey was developed via an electronic platform and answered by 91 out of 104 Greek residents from March 2019 until May 2019. Fisher's exact test, chi-squared test and Kruskal-Wallis test were used with statistical significance set at p=.05.

RESULTS

The median overall satisfaction regarding surgical training was 6/10 regardless of working schedule, working in a University Department, PGY or number of residents in clinic. Most residents have not performed any scrotal ultrasound or pressure-flow-studies; however, they are more familiar with KUB ultrasound. Double-J stent insertion and cystoscopy were common procedures for residents. Bureaucracy was reported as a major issue by 70.4% of residents. ESWL has not been performed by 80.2% of residents, 58.2% residents performed less than 10 ureteroscopies, and only the last year trainees performed more than 10 TURBT and TURP. Most residents mentioned to rarely perform basic steps in many open or laparoscopic urological procedures. Surprisingly, 59.3% of residents have not published any study in peer-reviewed journals. Regarding satisfaction, 44% rarely feel satisfied at work and 59.3% sometimes suffer from burnout. Response rate reached 87.5%.

CONCLUSIONS

Considering the results from this survey, regulatory authorities should join forces to establish a structured curriculum of clinical, surgical and research training in Urology across Europe.

The laboratory mouse and wild immunology

The laboratory mouse, Mus musculus domesticus, has been the workhorse of the very successful laboratory study of mammalian immunology. These studies--discovering how the mammalian immune system can work--have allowed the development of the field of wild immunology that is seeking to understand how the immune responses of wild animals contributes to animals' fitness. Remarkably, there have hardly been any studies of the immunology of wild M. musculus domesticus (or of rats, another common laboratory model), but the general finding is that these wild animals are more immunologically responsive, compared with their laboratory domesticated comparators. This difference probably reflects the comparatively greater previous exposure to antigens of these wild-caught animals. There are now excellent prospects for laboratory mouse immunology to make major advances in the field of wild immunology.

Acute myeloid leukaemia after treatment for acute lymphoblastic leukaemia in girl with Bloom syndrome

Bloom syndrome (BS) is an inherited genomic instability disorder caused by disruption of the BLM helicase and confers an extreme cancer predisposition. Here we report on a girl with BS who developed acute lymphoblastic leukaemia (ALL) at age nine, and treatment-related acute myeloid leukaemia (t-AML) aged 12. She was compound heterozygous for the novel BLM frameshift deletion c.1624delG and the previously described c.3415C>T nonsense mutation. Two haematological malignancies in a child with BS imply a fundamental role for BLM for normal haematopoiesis, in particular in the presence of genotoxic stress.

Gross rearrangements of the MECP2 gene are found in both classical and atypical Rett syndrome patients

MECP2 mutations are identifiable in approximately 80% of classic Rett syndrome (RTT), but less frequently in atypical RTT. We recruited 110 patients who fulfilled the diagnostic criteria for Rett syndrome and were referred to Cardiff for molecular analysis, but in whom an MECP2 mutation was not identifiable. Dosage analysis of MECP2 was carried out using multiplex ligation dependent probe amplification or quantitative fluorescent PCR. Large deletions were identified in 37.8% (14/37) of classic and 7.5% (4/53) of atypical RTT patients. Most large deletions contained a breakpoint in the deletion prone region of exon 4. The clinical phenotype was ascertained in all 18 of the deleted cases and in four further cases with large deletions identified in Goettingen. Five patients with large deletions had additional congenital anomalies, which was significantly more than in RTT patients with other MECP2 mutations (2/193; p<0.0001). Quantitative analysis should be included in molecular diagnostic strategies in both classic and atypical RTT.

Characterization of 34 novel and six known MTM1 gene mutations in 47 unrelated X-linked myotubular myopathy patients

X-linked myotubular myopathy (XLMTM) is a congenital muscle disorder mainly affecting newborn males. Neonatal muscle weakness and hypotonia usually leads to a rapid demise. The responsible gene, MTM1, was isolated in 1996, and mutational data derived from 90 patients have been published. We report on our findings in a further 53 patients, using genomic DNA and mRNA screening protocols. Thirty-four novel mutations were identified in 37 cases, and six known mutations found in 10 other patients. The 34 new mutations include five large deletions, eight nonsense, six frameshift, five missense, and eight splice-site mutations, whereas two intronic variants causing partial exon skipping represent the first report on such a mechanism in MTM1. Two deletions, one involving exon 1, and the second exon 15, are the first defects to be identified in these exons. The heterogeneity of the mutations, their mutational origins, and the varied ethnic backgrounds of the patients, indicate that the majority of XLMTM families are affected by unique MTM1 mutations.

Novel and recurrent mutations in the PKD1 (polycystic kidney disease) gene

A search has been conducted for disease-causing mutations in the PKD1 gene in 147 unrelated ADPKD index cases. Using the polymerase chain reaction with primer pairs located in the 3' single copy region of the gene and single-strand conformation polymorphism analysis, we detected novel aberrant bands in five individuals that were absent in 100 control samples. Sequencing revealed three nonsense mutations (Q4010X, E4024X, Q4041X), a frameshift mutation (12262 del 2 bp), and a missense mutation (G4031D). In addition, three polymorphisms were detected [12346 + 19delG, heterozygosity (0.13), I4044V (0.23), 12212-34C > A (0.07)]. The mutational mechanism for the recurrent mutation (Q4041X) is likely to be slipped mispairing of an adjacent direct imperfect repeat sequence.

Presymptomatic testing for Huntington's disease in Wales 1987-90

Between 1987 and 1990 a large series of at-risk individuals has been referred to our Huntington's disease (HD) presymptomatic testing programme. A detailed protocol for assessment and counselling has been followed. Out of 238 serious inquiries, 36% were potentially suitable for the testing programme, but 19% chose not to continue. Reasons for exclusion included the presence of clinical features of HD and being under the age of 18 years. Out of 40 final results given to 38 individuals, 23 indicated a lowered risk, 11 an increased risk, while five results were uninformative, two of these becoming informative on repeat testing. This series contained more women than men, and was disproportionately from the higher socio-economic groups. Motives for requesting a test principally related to child-bearing, informing existing children, and planning for the future. No significant psychiatric symptoms have been reported in the short term, but difficult counselling problems were presented by the high proportion of applicants who already showed clinical signs of HD. It is concluded that a detailed counselling protocol is essential in testing for HD, as many applicants are ill-prepared; this will assume even greater importance when the HD gene is identified and a test for specific mutations is available. The experience of presymptomatic testing for HD provides important general lessons which are likely to be applicable to other inherited neurological and psychiatric disorders.

Problems in genetic prediction for Huntington's disease

Experience with nearly 300 applicants for predictive testing for Huntington's disease has shown that apart from the expected problems such as those related to third-party interests and the effects of an adverse test result, there were several less foreseen difficulties. These included the finding that some applicants were already clinically affected, requests for testing of minors, unintentional risk alteration for relatives, and the use of research samples for service purposes. More of the problems involved clinical and counselling aspects rather than laboratory procedures.

Mutations for the autosomal recessive and autosomal dominant forms of polycystic kidney disease are not allelic

The autosomal dominant form of polycystic kidney disease (ADPKD) has been linked to the alpha-globin gene locus on 16p. Linkage studies between the autosomal recessive type (ARPKD) and the 3' HVR of the alpha-globin gene cluster showed that the ARPKD and ADPKD are not allelic.