To determine the prevalence of mitochondrial diseases (MD) in Hong Kong (HK) and to evaluate the clinical characteristics and genetic landscape of MD patients in the region.
This study ...retrospectively reviewed the phenotypic and molecular characteristics of MD patients from participating public hospitals in HK between January 1985 to October 2020. Molecularly and/or enzymatically confirmed MD cases of any age were recruited via the Clinical Analysis and Reporting System (CDARS) using relevant keywords and/or International Classification of Disease (ICD) codes under the HK Hospital Authority or through the personal recollection of treating clinicians among the investigators.
A total of 119 MD patients were recruited and analyzed in the study. The point prevalence of MD in HK was 1.02 in 100,000 people (95% confidence interval 0.81-1.28 in 100,000). 110 patients had molecularly proven MD and the other nine were diagnosed by OXPHOS enzymology analysis or mitochondrial DNA depletion analysis with unknown molecular basis. Pathogenic variants in the mitochondrial genome (72 patients) were more prevalent than those in the nuclear genome (38 patients) in our cohort. The most commonly involved organ system at disease onset was the neurological system, in which developmental delay, seizures or epilepsy, and stroke-like episodes were the most frequently reported presentations. The mortality rate in our cohort was 37%.
This study is a territory-wide overview of the clinical and genetic characteristics of MD patients in a Chinese population, providing the first available prevalence rate of MD in Hong Kong. The findings of this study aim to facilitate future in-depth evaluation of MD and lay the foundation to establish a local MD registry.
Newborn screening (NBS) is an important public health program that aims to identify pre-symptomatic healthy babies that will develop significant disease if left undiagnosed and untreated. The number ...of conditions being screened globally is expanding rapidly in parallel with advances in technology, diagnosis, and treatment availability for these conditions. In Hong Kong, NBS for inborn errors of metabolism (NBSIEM) began as a pilot program in October 2015 and was implemented to all birthing hospitals within the public healthcare system in phases, with completion in October 2020. The number of conditions screened for increased from 21 to 24 in April 2016 and then to 26 in October 2019. The overall recruitment rate of the NBS program was 99.5%. In the period between October 2015 and December 2022, 125,688 newborns were screened and 295 were referred back for abnormal results. The recall rate was reduced from 0.26% to 0.12% after the implementation of second-tier testing. An inherited metabolic disorder (IMD) was eventually confirmed in 47 infants, making the prevalence of IMD in Hong Kong 1 in 2674. At the time of the NBS result, 78.7% of the newborns with IMD were asymptomatic. There were two deaths reported: one newborn with methylmalonic acidemia cobalamin B type (MMACblB) died after the initial crisis and another case of carnitine palmitoyltransferase II deficiency (CPTII) died at 18 months of age after metabolic decompensation. The most common IMD noted were disorders of fatty acid oxidation metabolism (40%, 19 cases), closely followed by disorders of amino acid metabolism (38%, 18 cases), with carnitine uptake defect (19.1%, 9 cases) and citrullinemia type II (17%, 8 cases) being the two most common IMD picked up by the NBSIEM in Hong Kong. Out of the all the IMDs identified, 19.1% belonged to diverse ethnic groups. False negative cases were reported for citrullinemia type II and congenital adrenal hyperplasia during this period.
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Background: Inherited cancer genetic testing (CGT) is increasingly recommended in a wide range of settings to better evaluate and manage personal and/or family cancer risks. For ...individuals at risk, identification of monogenic risk factors by inherited CGT allows more appropriate advice, surveillance and targeted prevention. For cancer patients, inherited CGT provides guidance for the selection of targeted therapy treatment options. Little is known about the views of non-Western global communities, which can impact cancer prevention. We designed a DCE study to evaluate four key attributes to better target educational and policy interventions in an urban Asian community. Methods: We recruited healthy adults in the community aged between 21-60 in Singapore. Participants received basic information about cancer and cancer genetic testing, then completed a 16-task DCE survey that examined preferences for four attributes of cancer genetic testing for targeted prevention including: accuracy, waiting time for result, out-of-pocket cost and insurance claims. A conditional logit regression model was used to examine the main effect parameter, assuming all attributes have an independent influence on the participants’ preferences. Results: 93 adults were enrolled (71% female, 29% male). Attributes influencing decision to undergo inherited CGT in decreasing order of concern were accuracy (37%), out-of-pocket costs (22%), insurance claim (21%) and waiting time for result (20%). Increased out-of-pocket cost reduces the likelihood of people to go for testing (coef: -6.579e
−04
, p < 0.01). The impact of financial cost is less important for participants with increased monthly household income (coef: 1.791e
−04
, p < 0.01). Conclusions: With inherited cancer genetic testing becoming more common and relevant in terms of personal and/or family risk managements and guiding treatment options, this DCE study is helpful to guide clinicians tailor of individualized genetic counseling for non-Western communities, who may have different concerns from Western populations. Targeted policy intervention and education on these concerns may lead to greater accessibility for inherited CGT.
