Long-term effect of growth hormone on sleep-disordered breathing in Malaysian children with Prader-Willi syndrome: a retrospective study.

STUDY OBJECTIVES: The effect of recombinant human growth hormone (rhGH) on sleep-disordered breathing (SDB) in Malaysian children with Prader-Willi syndrome (PWS) is under-investigated. We determined (a) the short- and long-term effects of rhGH and (b) factors associated with worsening SDB, in children with PWS on rhGH. METHODS: This retrospective study included children with PWS (with and without rhGH) who had at least one polysomnography (PSG). Outcomes measured were the presence of SDB: before and after starting rhGH and the progress of SDB with and without rhGH. Serial insulin-like growth factor-1 (IGF-1) measurements were recorded. RESULTS: One-hundred and thirteen PSGs were analyzed. The majority (92.3%) of initial PSGs had SDB with AHI median (IQR) 5.0 (2.6,16.3) events/h. The age for receiving rhGH was median (IQR) 1.9 (0.7, 3.4) years old. A third (36.8%) had worsening SDB after initiating rhGH, which was associated with higher IGF-1 levels post-rhGH (p=0.007). After a median of 5 years of rhGH, 73.6% maintained or reduced their positive airway pressure (PAP) settings. Without rhGH, 80% had increased their PAP settings. Worsening SDB while on rhGH was associated with higher BMI, lower rhGH dose, higher IGF-1 levels and non-15q deletion. CONCLUSIONS: Majority of Malaysian children with PWS had SDB. At initiation rhGH, one-third of patients had worsening SDB, associated with increased IGF-1 levels. Stabilization of SDB was more frequently seen in those on long-term rhGH. Worsening SDB while on rhGH was associated with a higher BMI, on a lower dose of rhGH, higher IGF-1 levels and non-15q deletion.

Comparison of the ABC and ACMG systems for variant classification.

The ABC and ACMG variant classification systems were compared by asking mainly European clinical laboratories to classify variants in 10 challenging cases using both systems, and to state if the variant in question would be reported as a relevant result or not as a measure of clinical utility. In contrast to the ABC system, the ACMG system was not made to guide variant reporting but to determine the likelihood of pathogenicity. Nevertheless, this comparison is justified since the ACMG class determines variant reporting in many laboratories. Forty-three laboratories participated in the survey. In seven cases, the classification system used did not influence the reporting likelihood when variants labeled as "maybe report" after ACMG-based classification were included. In three cases of population frequent but disease-associated variants, there was a difference in favor of reporting after ABC classification. A possible reason is that ABC step C (standard variant comments) allows a variant to be reported in one clinical setting but not another, e.g., based on Bayesian-based likelihood calculation of clinical relevance. Finally, the selection of ACMG criteria was compared between 36 laboratories. When excluding criteria used by less than four laboratories (<10%), the average concordance rate was 46%. Taken together, ABC-based classification is more clear-cut than ACMG-based classification since molecular and clinical information is handled separately, and variant reporting can be adapted to the clinical question and phenotype. Furthermore, variants do not get a clinically inappropriate label, like pathogenic when not pathogenic in a clinical context, or variant of unknown significance when the significance is known.

GestaltMatcher Database - A global reference for facial phenotypic variability in rare human diseases.

The most important factor that complicates the work of dysmorphologists is the significant phenotypic variability of the human face. Next-Generation Phenotyping (NGP) tools that assist clinicians with recognizing characteristic syndromic patterns are particularly challenged when confronted with patients from populations different from their training data. To that end, we systematically analyzed the impact of genetic ancestry on facial dysmorphism. For that purpose, we established the GestaltMatcher Database (GMDB) as a reference dataset for medical images of patients with rare genetic disorders from around the world. We collected 10,980 frontal facial images - more than a quarter previously unpublished - from 8,346 patients, representing 581 rare disorders. Although the predominant ancestry is still European (67%), data from underrepresented populations have been increased considerably via global collaborations (19% Asian and 7% African). This includes previously unpublished reports for more than 40% of the African patients. The NGP analysis on this diverse dataset revealed characteristic performance differences depending on the composition of training and test sets corresponding to genetic relatedness. For clinical use of NGP, incorporating non-European patients resulted in a profound enhancement of GestaltMatcher performance. The top-5 accuracy rate increased by +11.29%. Importantly, this improvement in delineating the correct disorder from a facial portrait was achieved without decreasing the performance on European patients. By design, GMDB complies with the FAIR principles by rendering the curated medical data findable, accessible, interoperable, and reusable. This means GMDB can also serve as data for training and benchmarking. In summary, our study on facial dysmorphism on a global sample revealed a considerable cross ancestral phenotypic variability confounding NGP that should be counteracted by international efforts for increasing data diversity. GMDB will serve as a vital reference database for clinicians and a transparent training set for advancing NGP technology.

Case report: The evolving phenotype of ESCO2 spectrum disorder in a 15-year-old Malaysian child.

ESCO2 spectrum disorder is an autosomal recessive developmental disorder characterized by growth retardation, symmetrical mesomelic limb malformation, and distinctive facies with microcephaly, with a wide phenotypic continuum that ranges from Roberts syndrome (MIM #268300) at the severe end to SC phocomelia (MIM #269000) at the milder end. ESCO2 encodes a 601-amino acid protein belonging to the Eco1/Ctf7 family of acetyltransferases that is involved in the establishment of sister chromatid cohesion, which is essential for accurate chromosome segregation and genomic stability and thus belongs to a group of disorders called "cohesinopathies". We describe a 15-year-old Malaysian female who presented with the characteristic triad of ESCO2 spectrum disorder, with an equivocal chromosomal breakage study and normal karyotyping findings. She was initially suspected to have mosaic Fanconi anemia but whole exome sequencing (WES) showed a likely pathogenic homozygous splice variant c.955 + 2_955+5del in the ESCO2 gene. During the 15-year diagnostic odyssey, she developed type 2 diabetes mellitus, primary ovarian insufficiency, increased optic cup-to-disc ratio with tortuous vessels bilaterally, and an evolving but distinct facial and skin hypopigmentation phenotype. Of note, there was an absence of learning disabilities. Our findings provide further evidence for ESCO2 spectrum disorder in an Asian child and contribute to defining the clinical and radiographic spectrum.

Morbidity and treatment costs of cystic fibrosis in a middle-income country.

Introduction: : Asian children with cystic fibrosis (CF) managed in Malaysia have significant morbidity with limited access to life-sustaining treatments. We determined the morbidity and treatment cost of CF in a resource-limited country. Methods: This cross-sectional study included all children diagnosed with CF in our centre. Data on clinical presentation, genetic mutation, serial spirometry results and complications were collected. Out-of-pocket (OOP) and healthcare costs over 1 year were retrieved for patients who were alive. Cohen's d and odds ratio (OR) were used to determine the effect size. Results: Twenty-four patients were diagnosed with CF. Five patients died at a median (range) age of 18 (0.3-22) years. F508deletion (c. 1521_1523delCTT) was found in 20% of the alleles, while 89% of the variants were detected in nine patients. Body mass index (BMI) Z score was >-1.96 in 70.6% of patients. Two thirds (68%) were colonised with Pseudomonas aeruginosa, and this was associated with lower weight (P = 0.009) and BMI (P = 0.02) Z scores. Only 18% had FEV1 Z scores >-1.96. Early symptom onset (d = 0.74), delayed diagnosis (d = 2.07), a low FEF25-75 Z score (d = 0.82) and a high sweat conductance (d = 1.19) were associated with death. Inpatient cost was mainly from diagnostic tests, while medications contributed to half of the outpatient cost.Healthcare utilisation cost was catastrophic, amounting to 20% of the total income. Conclusion: Asian children with CF suffer significant complications such as low weight, low lung function and shortened lifespan. P. aeruginosa colonisation was frequent and associated with poor growth. Healthcare cost to parents was catastrophic.

Infantile neuroaxonal dystrophy in a pair of Malaysian siblings with progressive cerebellar atrophy: Description of an expanded phenotype with novel PLA2G6 variants.

Infantile neuroaxonal dystrophy 1 (INAD) (OMIM #256600) is a rare infantile onset neurodegenerative disease characterised by neuroregression and hypotonia, evolving into generalized spasticity, blindness and dementia. We report our diagnostic approach of a pair of siblings with psychomotor regression, hypotonia, optic atrophy and auditory neuropathy. The brain magnetic resonance imaging (MRI) showed progressive cerebellar atrophy. Genetic testing of the PLA2G6 confirmed presence of compound heterozygous novel mutations. As the variant c. 196C>T (p.Gln66X) was a truncating variant, it was considered as pathogenic while the variant c. 2249G>A (p. Cys750Tyr) was considered as "likely pathogenic" by bioinformatics analyses. Our patient expands the clinical phenotype of INAD as it described the first South-East Asian patient with INAD-associated auditory neuropathy. Our report highlights the importance of increased awareness of this condition amongst clinicians, the use of deep phenotyping using neuroimaging and the clinical utility of gene sequencing test in the delineation of syndromes associated with infantile neurodegenerative disease.