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This study aims to give an overview of the number of prenatal tests for Huntington's disease ( HD), test results, and pregnancy outcomes in the Netherlands between 1998 and 2008 and to compare them with available data from the period 1987 to 1997. A total of 126 couples underwent prenatal diagnosis ( PND) on 216 foetuses: 185 (86%) direct tests and 31 (14%) exclusion tests. In 9% of direct tests the risk for the foetus was 25%. Four at-risk parents (4%) carried intermediate alleles. Ninety-one foetuses had CAG expansions ≥36% or 50% risk haplotypes: 75 (82%) were terminated for HD, 12 (13%) were carried to term; four pregnancies were miscarried, terminated for other reasons or lost to follow-up. Unaffected pregnancies (122 foetuses) resulted in the birth of 112 children. The estimated uptake of PND was 22% of CAG expansion carriers (≥36 repeats) at reproductive age. PND was used by two new subgroups: carriers of intermediate alleles and 50% at-risk persons opting for a direct prenatal test of the foetus. A significant number of HD expansion or 50% risk pregnancies were continued. Speculations were made on causative factors contributing to these continuations. Further research on these couples' motives is needed. [ABSTRACT FROM AUTHOR]

We aimed to study reproductive behaviour of couples opting for prenatal diagnosis ( PND) and pre-implantation genetic diagnosis ( PGD) for Huntington's disease ( HD). In the Netherlands, exclusion PND is available for persons at 50% risk, whereas exclusion PGD is not allowed. All 162 couples who underwent PND or PGD for HD between 1998 and 2008 and referrals for exclusion PGD to Belgium were included. Couples' reproductive information was collected until December 2010; 132 couples (81.5%) underwent PND in 262 pregnancies, 54 (33.3%) started PGD, and 25 used both. Sixteen percent of PND couples used exclusion PND and 6% used exclusion PGD. The outcomes were 76.5% of PND couples delivered ≥1 unaffected child(ren) after PND, and 44.4% of PGD couples delivered ≥1 PGD child(ren) (mean 2.5 cycles/couple). Couples opting for PGD secondarily (after a previous pregnancy) had more frequently terminated a pregnancy for HD (87.0%) compared with couples secondarily opting for PND (55.2%; p = 0.015). At-risk or HD expansion carrier males were underrepresented in the group of couples primarily opting for PGD (25%) and overrepresented in the secondary PGD group (64%). We conclude that couples reconsider their choices in every subsequent pregnancy based on their previous experience, personal beliefs and the gender of the at-risk partner. [ABSTRACT FROM AUTHOR]

van Rij MC, de Die-Smulders CEM, Bijlsma EK, de Wert GMWR, Geraedts JP, Roos RAC, Tibben A. Evaluation of exclusion prenatal and exclusion preimplantation genetic diagnosis for Huntington's disease in the Netherlands. Individuals at 50% risk of Huntington's disease (HD) who prefer not to know their carrier status, might opt for exclusion prenatal diagnosis (ePND) or exclusion preimplantation genetic diagnosis (ePGD). This study aims to provide a better understanding of couples' motives for choosing ePND or ePND, and surveys couples' experiences in order to make recommendations for the improvement of counselling for exclusion testing. This qualitative retrospective interview study focussed on couples who underwent ePND or ePGD for HD in the period 1996-2010. Seventeen couples were included of which 13 had experienced ePND and 6 ePGD. Mean time-interval since exclusion-testing was 3.9 years. Couples' moral reservations regarding termination of pregnancy (TOP) or discarding healthy embryos were counterbalanced by the wish to protect their future child against HD. Seven couples had terminated a total of 11 pregnancies with a 50% HD risk, none showed regret. ePGD was used by couples who wanted to avoid (another) TOP. ePND and ePGD are acceptable reproductive options for a specific group of counsellees. To guarantee sound standards of care, it is imperative that candidate couples be given in-depth non-directive counselling about all possible scenarios, and adequate professional and psychological support prior to, during and after ePND/ePGD. [ABSTRACT FROM AUTHOR]

Background: Juvenile-onset Huntington's disease (JHD) represents 1-5% of Huntington's disease (HD) patients, with onset before the age of 21. Pediatric HD (PHD) relates to a proportion of JHD patients that is still under 18 years of age. So far, both populations have been excluded from interventional trials., Objective: Describe the prevalence and incidence of JHD and PHD in the Netherlands and explore their ability to participate in interventional trials., Methods: The prevalence and incidence of PHD and JHD patients in the Netherlands were analyzed. In addition, we explored proportions of JHD patients diagnosed at pediatric versus adult age, their diagnostic delay, and functional and modelled (CAP100) disease stage in JHD and adult-onset HD patients at diagnosis., Results: The prevalence of JHD and PHD relative to the total manifest HD population in January 2024 was between 0.84-1.25% and 0.09-0.14% respectively. The mean incidence of JHD patients being diagnosed was between 0.85-1.28 per 1000 patient years and of PHD 0.14 per 1.000.000 under-aged person years. 55% of JHD cases received a clinical diagnosis on adult age. At diagnosis, the majority of JHD patients was functionally compromised and adolescent-onset JHD patients were significantly less independent compared to adult-onset HD patients., Conclusions: In the Netherlands, the epidemiology of JHD and PHD is lower than previously suggested. More than half of JHD cases are not eligible for trials in the PHD population. Furthermore, higher functional dependency in JHD patients influences their ability to participate in trials. Lastly, certain UHDRS functional assessments and the CAP100 score do not seem appropriate for this particular group.