Marcela Gargiulo

Long-term outcome of presymptomatic testing in Huntington disease

Our study on long-term outcome of presymptomatic testing for Huntington disease had two aims: the comparison of the psychological well-being and social adjustment of carriers and non-carriers of the mutation, and the identification of psychological determinants to improve care/support of testees. We performed a cross-sectional study of 351 persons who underwent presymptomatic testing. Those who had motor signs were excluded from the comparison of asymptomatic carrier and non-carriers. A structured interview including five self-report scales and the MINI (Mini International Neuropsychiatric Inventory) was proposed to detect a psychopathology or problem with social adjustment.We interviewed 119 testees (53%), 62 non-carriers and 57 carriers after a mean delay of 3.7 years (range: 0.32 to 8.9) after their result. Depression was frequent in asymptomatic carriers (58%). Interestingly, the self reported impact of the test showed that 27% of non-carriers did not cope well with a favourable result, and a significant percentage of non-carriers (24%) were depressed during follow-up. Multivariate analysis showed that only a previous episode of depression was predictive of depression after genetic testing in both carriers and non-carriers of the HD mutation (P<0.0001).Psychological support is necessary for all testees regardless of the result of their presymptomatic test, because psychiatric care is often needed by both carriers and non-carriers.

Genetic testing and genetic counselling in hypertrophic cardiomyopathy: the French experience

Aims: A major breakthrough in the molecular genetics of hypertrophic cardiomyopathy (HCM) has made genetic testing now available in clinical practice, raising new questions about its implications, potential benefits, and the organisation of the procedure. The aim of this work was (1) to discuss the different questions related to genetic testing in HCM, and propose guidelines for the different situations, (2) to report our preliminary experience with a specific procedure. Methods and results: The main questions asked by patients and relatives concern presymptomatic diagnosis and prenatal counselling/diagnosis, while clinicians sometimes discuss diagnostic and prognostic testing. To take into account the complex medical and psychological implications of this new approach, we developed a specific, multidisciplinary, and multiple step procedure, including a cardiologist, a geneticist, and a psychologist. Seventy subjects were examined, including (1) 29 adults for presymptomatic diagnosis (of whom 10 left the procedure after the first visit and 19 continued, among whom six had a mutation and two experienced negative psychological impact, observed during follow up), (2) nine couples of parents for presymptomatic diagnosis in their children (the procedure was stopped after the first visit in eight and continued in one), (3) 22 couples for prenatal counselling (no prenatal genetic testing was asked for after the first visit), and (4) 10 subjects for diagnostic testing. We decided to perform no prognostic testing. Conclusion: Our preliminary experience confirms the complexity of the situation and suggests the necessity for a specific procedure to ensure good practice in genetic testing of HCM.

Cognitive profile in childhood myotonic dystrophy type 1: Is there a global impairment?

The objective of this study was to assess the cognitive profile in the childhood-onset form of myotonic dystrophy (DM1). We carried out a general cognitive abilities study on 36 patients (6-18 years). Results of Full Scale IQ , VIQ (Verbal IQ) and PIQ (Performance IQ) measures are discussed in terms of global cognitive impairment depending on the (CTG)n repeat size and the transmitting parents sex. The results highlighted a negative correlation between the CTG repeat size and cognitive function: (1) 55% of the subjects (20/34) presented large CTG expansion (mean=761) correlated with significant extensive cognitive deficits (mean Full Scale IQ=56) in both intelligence scales (verbal and non-verbal); most of them exhibited DM1 maternal transmission. (2) In the case of smaller expansion (mean=527), 38% of the subjects exhibited a subnormal intelligence (mean Full Scale IQ=86) but performed poorly on subtests evaluating attention/memory function and presented a severe deficit in visuospatial and/or visuo-constructive skills. Most of these children had paternal transmission but a few had an affected mother.

A new window on neurocognitive dysfunction in the childhood form of myotonic dystrophy type 1 (DM1)

Not much is known about the neurocognitive deficits in the childhood phenotypic expression of DM1. Twenty-four children and adolescents with no mental retardation were administered an extensive neuropsychological battery to investigate cognition in terms of memory, executive functions and visuo-spatial abilities. The results showed discrepancies between Wechslers indexes with higher scores in Verbal Comprehension than Perceptive Organization and Speed of Processing. Memory assessment using Signorets Memory Battery revealed a clear difference between verbal and visuospatial memory but no impairment between short and long-term memory. Concerning executive abilities, DM1 subjects showed greater deficits in processing speed than in mental flexibility, inhibition or working memory. This pattern of deficits could implicate a frontoparietal circuit in accordance with the neural networks involved in the adult form of DM1 and reopens the question of a continuum between childhood and adulthood neurocognitive impairments.

Is non-recognition of choreic movements in Huntington disease always pathological?

Clinical experience and prior studies suggest that Huntington disease (HD) patients have low insight into their motor disturbances and poor real-time awareness (concurrent awareness) of chorea. This has been attributed to sensory deficits but, until now, concurrent awareness of choreic movements has not been compared to the degree of insight that presymptomatic carriers of the HD gene and healthy control subjects have into non-pathological involuntary movements. To further investigate loss of insight into motor dysfunction in HD patients, we administered a video-recorded interview and 4 experimental tasks to 68 subjects from the TRACK-HD cohort, including 28 high-functioning patients in early stages of HD, 28 premanifest mutation carriers and 12 controls. All underwent full neurological and neuropsychological evaluations and 3T MRI examinations. Subjects were asked to assess the presence, body location, frequency, practical consequences and probable causes of motor impairments, as well as the presence and body location of involuntary movements during 4 experimental tasks. The accuracy of their judgments, assessed by comparison with objective criteria, was used as a measure of their insight into motor disturbances and of their concurrent awareness of involuntary movements. Insight was poor in early HD patients: motor symptoms were nearly always underestimated. In contrast, concurrent awareness of involuntary movements, although also poor, was essentially indistinguishable across the 3 groups of subjects: non-pathological involuntary movements were as difficult to perceive by controls and premanifest carriers as was chorea for early HD patients. GLM analysis suggested that both concurrent awareness and perception of practical consequences of movement disorder had a positive effect on intellectual insight, and that mental flexibility is involved in concurrent awareness. Our results suggest that low insight into motor dysfunction in early HD, although marginally modulated by cognitive factors, is mainly non-pathological, and parallels a general tendency, shared by healthy subjects, to neglect self-generated involuntary movements in real time. This tendency, combined with the paucity of functional consequences of incipient chorea, could explain the difficulty of its discovery by the patients.

Childhood onset-form of myotonic dystrophy type 1 and autism spectrum disorders: is there comorbidity?

Myotonic dystrophy type 1 (DM1) is a multisystemic disorder with neuromuscular symptoms and brain dysfunctions. Depending on the phenotypic expression, the degree of cognitive impairment remains heterogeneous, ranging from moderate to severe intellectual disability in the congenital form, to executive, visuospatial and personality dysfunction in the adult-onset form. Studies exploring the cognitive or psychiatric impairments in the childhood form of DM1, characterized by an age of onset between one and ten years, uneventful pre and post natal history and normal development the first year of life, are scarce and show conflicting results in regard to a comorbid diagnosis of Autism Spectrum Disorder (ASD). The aim of the current review is to summarize diagnostic criteria and update the state of the debate regarding comorbidity. Evidence from 9 studies collected in PubMed database (representing a total of 175 cases) focusing on clinical, neuropsychological and neuroimaging domains in childhood DM1 is considered and similarities or differences between childhood DM1 and ASD are identified. Highlighting what is known about the neurocognitive features specific to the childhood-onset form of DM1 could help (1) propose early screening regarding socio-emotional and attentional/executive functions or (2) implement therapeutic programs based on reinforcement of executive skills or social cognition.

A liminal stage after predictive testing for Huntington disease

Background Following predictive testing for Huntington disease (HD), knowledge of ones carrier status may have consequences on disease onset. Our study aimed to address two questions. First, does knowledge of being a carrier of the pathological HD mutation trigger onset of the disease? Second, does this knowledge influence self-awareness and allow carriers to identify signs and symptoms of disease onset? Methods Between 2012 and 2015, 75 HD mutation carriers were examined using the Unified Huntingtons Disease Rating Scale (UHDRS) motor score. Onset estimation made with the disease burden score was compared with UHDRS findings. We collected qualitative data with questionnaires and semistructured interviews. Results 38 women and 37 men, aged 43.7 years±10.5 (20–68), were interviewed after a mean delay between test and study interview of 10.5 years±4.7 (from 4 to 21 years). Estimation of age at onset was 4.5±8.5 years earlier than data-derived age at onset. Participants were categorised according to their motor score: scores <5 were premanifest (n=35), and scores >5 were manifest carriers (n=40). Self-observation was a major preoccupation for all, independent of their clinical status (82% vs 74%, p=0.57). Among manifest carriers, 56% thought they showed symptoms, but only 33% felt ill. Interestingly, this was also observed in those without motor signs (20% and 9%). Being a mutation carrier did not significantly facilitate recognition of motor signs. Interviews with premanifest carriers allowed the burden of self-observation to be illustrated despite lack of motor signs. Conclusions Estimating age at onset based on disease burden score may not be accurate. The transition to disease was experienced as an ambiguous or liminal experience. The view of mutation carriers is not always concordant with medical onset estimation, highlighting the difficulties involved in the concept of onset and its use as an outcome in future disease-modifying trials.

Personality and Neuropsychological Profiles in Friedreich Ataxia

Friedreich ataxia, an autosomal recessive mitochondrial disease, is the most frequent inherited ataxia. Many studies have attempted to identify cognitive and affective changes associated with the disease, but conflicting results have been obtained, depending on the tests used and because many of the samples studied were very small. We investigated personality and neuropsychological characteristics in a cohort of 47 patients with genetically confirmed disease. The neuropsychological battery assessed multiple cognition domains: processing speed, attention, working memory, executive functions, verbal memory, vocabulary, visual reasoning, emotional recognition, and social cognition. Personality was assessed with the Temperament and Character Inventory, and depressive symptoms were assessed with the Beck Depression Inventory. We found deficits of sustained attention, processing speed, semantic capacities, and verbal fluency only partly attributable to motor deficit or depressed mood. Visual reasoning, memory, and learning were preserved. Emotional processes and social cognition were unimpaired. We also detected a change in automatic processes, such as reading. Personality traits were characterized by high persistence and low self-transcendence. The mild cognitive impairment observed may be a developmental rather than degenerative problem, due to early cerebellum dysfunction, with the impairment of cognitive and emotional processing. Disease manifestations at crucial times for personality development may also have an important impact on personality traits.

Reverse pre-symptomatic testing for Huntington disease: double disclosure when 25% at-risk children reveal the genetic status to their parent

Predictive testing for Huntington disease (HD) in 25% at-risk individuals is testing with full knowledge, and sometimes assuming, that the parent does not want to know his status. The goal of this study was to understand: (1) the differences in the motivation between 25% and 50% at-risk individuals to be tested and (2) the consequences of “double disclosure”, including parental reactions. Test requests from 25% at-risk individuals were rare (155/1611, 10%). We compared their motivation with those of 1456 50% at-risk individuals. The principal motivation to have the test for both groups was “to know” (48% versus 58%, p = 0.049), but the desire to have children was more frequent in the 25% at-risk group (32% versus 17%, p < 0.001). Sixty percent of the 25% at-risk group went through the testing procedure: 15% (n = 14) were variant positive for HD. Testees reported four adverse reactions of their parent (22%): one committed suicide and three became depressed. This result highlights the impact of “double disclosure”, a bad result for the person themselves and the transmitting parent. It is the responsibility of the team to anticipate this outcome with the 25% at-risk individuals: children revealing the genetic status to their parent. They should help the testees and their family to find a satisfactory solution to help prevent adverse reactions. This includes ensuring that the candidate is well-infomed abour the testing options and consequences to her/himself but also to her/his parent. The at-risk parent should be offered to discuss the implications of their child’s testing.

Prenatal testing in Huntington disease: after the test, choices recommence.

The objective of this study was (1) to determine the impact of prenatal diagnosis (PND) for Huntington disease (HD) on subsequent reproductive choices and family structure; and (2) to assess whether children born after PND were informed of their genetic status. Out of 354 presymptomatic carriers of HD gene mutation, aged 18–45 years, 61 couples requested 101 PNDs. Fifty-four women, 29 female carriers and 25 spouses of male carriers, accepted to be interviewed (0.6–16.3 years after the last PND, median 6.5 years) on their obstetrical history and information given to children born after PND. Women were willing to undergo two or more PNDs with a final success rate of 75%. Reproductive decisions differed depending on the outcome of the first PND. If favourable, 62% couples decided against another pregnancy and 10% chose to have an untested child. If unfavourable, 83% decided for another pregnancy (P<0.01), and the majority (87%) re-entered the PND procedure. In contrast, after a second PND, only 37% asked for a PND and 30% chose to have an untested child. Thirty-three percent had both, tested and untested children. Among children born after PND, 10 years and older, 75% were informed of their genetic status. The decision to prevent transmission of the HD mutation is made anew with each pregnancy. Couples may need more psychological support after PND and pre-counselling sessions should take into account the effect of the outcome of a first PND on subsequent reproductive choices.