Genetic care in geographically isolated small island communities: 8 years of experience in the Dutch Caribbean.

Worldwide, there are large inequalities in genetic service delivery. In 2011, we established a bi-annual joint pediatric-genetics clinic with a visiting clinical geneticist in the Dutch Caribbean. This retrospective study evaluates the yield of diagnostic testing and the clinical utility of a diagnosis for patients with rare diseases on these relatively isolated, resource-limited islands. A total of 331 patients that were referred to the clinical geneticist between November 2011 and November 2019 and had genetic testing were included in this study. A total of 508 genetic tests were performed on these patients. Microarray, next-generation sequencing gene panels, and single-gene analyses were the most frequently performed genetic tests. A molecularly confirmed diagnosis was established in 33% of patients (n = 108). Most diagnosed patients had single nucleotide variants or small insertions and/or deletions (48%) or copy number variants (34%). Molecular diagnostic yield was highest in patients referred for seizures and developmental delay/intellectual disability. The genetic diagnosis had an impact on clinical management in 52% of patients. Referrals to other health professionals and changes in therapy were the most frequently reported clinical consequences. In conclusion, despite limited financial resources, our genetics service resulted in a reasonably high molecular diagnostic yield. Even in this resource-limited setting, a genetic diagnosis had an impact on clinical management for the majority of patients. Our approach with a visiting clinical geneticist may be an example for others who are developing genetic services in similar settings.

The clinical practice guideline palliative care for children and other strategies to enhance shared decision-making in pediatric palliative care; pediatricians' critical reflections.

BACKGROUND: Because of practice variation and new developments in palliative pediatric care, the Dutch Association of Pediatrics decided to develop the clinical practice guideline (CPG) palliative care for children. With this guideline, the association also wanted to precipitate an attitude shift towards shared decision-making (SDM) and therefore integrated SDM in the CPG Palliative care for children. The aim was to gain insight if integrating SDM in CPGs can potentially encourage pediatricians to practice SDM. Its objectives were to explore pediatricians' attitudes and thoughts regarding (1) recommendations on SDM in CPGs in general and the guideline Palliative care for children specifically; (2) other SDM enhancing strategies or tools linked to CPGs. METHODS: Semi-structured face-to-face interviews. Pediatricians (15) were recruited through purposive sampling in three university-based pediatric centers in the Netherlands. The interviews were audio-recorded and transcribed verbatim, coded by at least two authors and analyzed with NVivo. RESULTS: Some pediatricians considered SDM a skill or attitude that cannot be addressed by clinical practice guidelines. According to others, however, clinical practice guidelines could enhance SDM. In case of the guideline Palliative care for children, the recommendations needed to focus more on how to practice SDM, and offer more detailed recommendations, preferring a recommendation stating multiple options. Most interviewed pediatricians felt that patient decisions aids were beneficial to patients, and could ensure that all topics relevant to the patient are covered, even topics the pediatrician might not consider him or herself, or deems less important. Regardless of the perceived benefit, some pediatricians preferred providing the information themselves instead of using a patient decision aid. CONCLUSIONS: For clinical practice guidelines to potentially enhance SDM, guideline developers should avoid blanket recommendations in the case of preference sensitive choices, and SDM should not be limited to recommendations on non-treatment decisions. Furthermore, preference sensitive recommendations are preferably linked with patient decision aids.

Biallelic loss-of-function P4HTM gene variants cause hypotonia, hypoventilation, intellectual disability, dysautonomia, epilepsy, and eye abnormalities (HIDEA syndrome).

PURPOSE: A new syndrome with hypotonia, intellectual disability, and eye abnormalities (HIDEA) was previously described in a large consanguineous family. Linkage analysis identified the recessive disease locus, and genome sequencing yielded three candidate genes with potentially pathogenic biallelic variants: transketolase (TKT), transmembrane prolyl 4-hydroxylase (P4HTM), and ubiquitin specific peptidase 4 (USP4). However, the causative gene remained elusive. METHODS: International collaboration and exome sequencing were used to identify new patients with HIDEA and biallelic, potentially pathogenic, P4HTM variants. Segregation analysis was performed using Sanger sequencing. P4H-TM wild-type and variant constructs without the transmembrane region were overexpressed in insect cells and analyzed using sodium dodecyl sulfate-polyacrylamide gel electrophoresis and western blot. RESULTS: Five different homozygous or compound heterozygous pathogenic P4HTM gene variants were identified in six new and six previously published patients presenting with HIDEA. Hypoventilation, obstructive and central sleep apnea, and dysautonomia were identified as novel features associated with the phenotype. Characterization of three of the P4H-TM variants demonstrated yielding insoluble protein products and, thus, loss-of-function. CONCLUSIONS: Biallelic loss-of-function P4HTM variants were shown to cause HIDEA syndrome. Our findings enable diagnosis of the condition, and highlight the importance of assessing the need for noninvasive ventilatory support in patients.

PDE3A gene screening improves diagnostics for patients with Bilginturan syndrome (hypertension and brachydactyly syndrome).

Autosomal-dominant hypertension and brachydactyly syndrome (HTNB; Bilginturan syndrome) is known to cause stroke before age 50 when untreated. We report a novel PDE3A gene mutation in a mother and daughter affected with dominant brachydactyly of the hands and feet, a short stature, and hypertension. The hypertension was medically responsive to anti-hypertensive treatment. The 3-bp deletion in the PDE3A gene presented de novo in the mother. Here, we expand the list of PDE3A mutations identified in Bilginturan syndrome and emphasize the importance of standardized genetic testing of HTNB patients to improve diagnostics at an early age. We recommend extended phenotyping in patients with brachydactyly, a short stature or hypertension in clinical practice.