Comment on prevalence of hereditary prosopagnosia (HPA) in Hong Kong Chinese population

Kennerknecht et al. [Kennerknecht et al. (2008); Am J Med Genet Part A 146A] estimate that 1.9% of the Chinese population are hereditary prosopagnosics. I discuss concerns about their assumption that the great majority of prosopagnosia resulting from developmental problems are heritable and present data from my laboratory that suggests that a considerable proportion of developmental prosopagnosics do not have relatives who share their face recognition deficits.     

First report of prevalence of non-syndromic hereditary prosopagnosia (HPA)

Acquired prosopagnosia (PA) is a rare condition after, for example, a stroke or brain injury. The congenital form of PA is generally considered to be even less common. Beside a few single case reports and anecdotal mentioning of familial cases no data on the epidemiology exists. Following a questionnaire-based screening in local secondary schools and at our medical faculty, candidates suspicious for PA underwent a semi-structured interview followed by examinations of first degree relatives. Among 689 local pupils and medical students of our university we found 17 with congenital PA. This corresponds to a prevalence rate of 2.47% (95% CI 1.31-3.63). The frequency is among the highest known for a monogenic disorder. All those index subjects (n = 14) of the target group who agreed to further examinations of their family members had other first degree relatives with the same cognitive disorder. This study provides epidemiological evidence that congenital PA is a very common cognitive disorder which almost always runs in families. The segregation pattern of this hereditary prosopagnosia (HPA) is fully compatible with autosomal dominant inheritance.     

Hereditary prosopagnosia (HPA): the first report outside the Caucasian population

Prosopagnosia (PA) or face blindness is characterized by a deficiency in identifying familiar faces. Almost all reports are single cases or collections of unrelated patients who acquired prosopagnosia after brain injuries, strokes or atrophy of at least the right occipito-temporal cortex. Until 2001, the inborn form—in the absence of any brain lesions—was described in fewer than 20 probands exclusively of Caucasian origin. We recently found that in the German Caucasian population, congenital prosopagnosia has a very high prevalence of at least 2.5% and that it is genetically determined. It is best described by autosomal-dominant inheritance in the more than 50 families investigated. We therefore introduced the term non-syndromic hereditary PA for the congenital form of a monosymptomatic or isolated PA. This surprisingly high frequency in the Caucasian population prompted us to extend our search to other ethnic groups. We performed a questionnaire-based screening among 198 native Indian students at Banaras Hindu University in Varanasi. In a then selected subset, we found after further detailed diagnostic interviews one Bengali female student with visual agnosia for face recognition only. Several other members of her large family reported the same impairment of face recognition. The segregation pattern of PA in this family is also compatible with autosomal-dominant inheritance.     

The prevalence of osteoporosis in the Hong Kong Chinese female population

Objectives: This paper aims to present population-based age-related bone mass values in the Hong Kong Chinese female population, and to assess the number and proportion of Chinese women considered osteoporotic according to the WHO diagnostic guidelines. Methods: A total of 769 community-based female subjects were recruited. Social demographic characteristics of these subjects were similar to the Hong Kong general population. All bone mass measurements were performed by means of a dual energy X-ray densitometry (Norland XR 26) at two sites: lumbar vertebrae L2–L4 and left hip. These values were expressed as T-scores, with reference to the mean bone mineral density (BMD) values of the group aged 21–40 years. Results: The study revealed that, in women aged 60 years and above, their mean BMD values are 30% lower than the young normal mean. The prevalence of osteoporosis at the spine increased dramatically from about 10% in the age group 50–59 to 45% in the group aged 60–69. In women aged 70 onwards, over half have osteoporosis at the hip. The prevalence of osteoporosis at the spine is relatively stable in the age groups above 60, while that for osteoporosis at the hip increased exponentially with age. Conclusions: The prevalence of osteoporosis in Hong Kong women is comparable to that found in Caucasian populations. Prevention of osteoporosis, involving both immediate and long-term measures, and targeting at different age groups, are required to combat this serious public health problem in Hong Kong.     

AIDS in a Hong Kong Chinese

A young Hong Kong Chinese male patient with fever of unknown origin is presented. The diagnosis of acquired immunodeficiency syndrome was made only 5 months after the onset of his illness. The lack of awareness of the syndrome might account for the delay in the diagnosis. The legal attitude towards homosexuality might have an adverse effect on epidemiological studies of AIDS in Hong Kong.     

Prevalence of latex allergy in hospital staff in Hong Kong

Background The prevalence of latex allergy in healthcare workers in Asian populations is unknown. Methods We studied 1472 employees in a teaching hospital in Hong Kong using written questionnaires and 133 respondents underwent skin prick testing to latex glove eluates and common allergens. Results Glove-related symptoms were common and 455 (30.9%) reported one or more symptoms, the majority of which could be classified as glove dermatitis (GD). On the other hand, symptoms suggestive of latex allergy such as urticaria, rhinitis, wheeze and asthma, were encountered less frequently and were noted by 3.3%. In particular, one developed asthma and two had wheezing, but there was no report of anaphylaxis. A total of 9.9% reported allergic symptoms from contact with other latex devices, in particular, rubber bands, rubber boots, goggles and swimming. Nine subjects (6.8%) had positive skin test to one or more of the five latex extracts. All were atopic to common allergens. Skin test positivity to latex and banana extracts was positively correlated (P < 0.05). In univariate logistic regression, daily glove use, personal history of allergic disease and history of allergic symptoms to latex-containing devices other than gloves were significant risk factors for both GD and LA. Nurses were more likely to complain of GD and workers with positive skin test to latex were 8.6 times more likely to have symptoms of LA. In multiple logistic regression, the remaining significant associations were between history of daily glove use and GD (OR = 50.11, 95% CI 15.88–158.13), and between positive latex skin test and LA (OR = 8.14, 95% CI 1.27–52.36). Conclusion Glove-related symptoms are common in healthcare workers in Hong Kong. Gloved healthcare workers are at risk of becoming sensitized to latex, and those with positive latex skin tests, long glove exposure time and frequent glove changes are at risk of clinical latex allergy.     

香港地区1022例中医体质流行病学调查

目的研究香港地区一般人群的中医体质类型分布状况,分析香港地区不同社会人口学人群体质类型的特征。结论针对香港地区一般人群,填写＂中医体质调查表＂收集数据,应用判别分析法判定个体体质类型,利用χ2检验分析其中医体质类型与性别、年龄、文化程度、职业等因素的相关性。结果香港地区一般人群中平和质占46.77%、8种偏颇体质占55.24%;8种偏颇体制中居于前3位的体质类型是阳虚质（9.88%）、气虚质（9.59%）及湿热质（8.22%）;不同的体质类型构成比不同,差异具有统计学意义（P〈0.01）。结论香港地区一般人群中约1/2人群为平和体质,约1/2为偏颇体质,偏颇体质中阳虚质、气虚质及湿热质较多见。不同性别、年龄、文化程度、职业等人群的体质特点不同。     

Nonbacterial thrombotic endocarditis in Hong Kong Chinese

Fifty-two Hong Kong Chinese cases of nonbacterial thrombotic endocarditis at autopsy were reviewed to ascertain if there was any difference in autopsy incidence, associated diseases, age and sex incidence, distribution of infarcts, and pattern of valve involvement compared with that in previously reported series. The overall autopsy incidence was 0.68%, within the range of previous reports. Forty-one cases (79%) were associated with malignant neoplasms; the remaining 11 cases were associated with miscellaneous disorders. Adenocarcinoma was associated with 27 (52%) of the cases. Unusual findings were the association of five cases with intrahepatic cholangiocarcinoma and four cases with esophageal squamous carcinoma. This is explicable on the basis of a higher incidence of these two tumors in Hong Kong Chinese than in Western populations, ie, the source of most other reported series. Sex and age incidence, the distribution of infarcts, and the pattern of valve involvement were similar to those reported in other series of nonbacterial thrombotic endocarditis.     

Analysis of TGF-beta(1) gene polymorphisms in Hong Kong Chinese patients with asthma

BACKGROUND: The C-509T polymorphism of TGF-beta(1) gene has been associated with asthma and atopy in white populations. OBJECTIVE: We investigated the association between asthma and previously identified polymorphisms at C-509T and T869C of the TGF-beta(1) gene among 250 Chinese patients with asthma and 308 healthy controls in Hong Kong. METHODS: Genotyping was performed on peripheral blood genomic DNA by using PCR-RFLP. RESULTS: There were no differences in the frequencies of genotypes and alleles between patients and controls. The C-509T and T869C polymorphisms were in tight linkage disequilibrium (P < .01). Among atopic subjects, significant differences were found in genotype and allele frequencies for T869C polymorphism between patients and controls (P = .014 and P = .019, respectively), and individuals bearing the CC genotype were associated with increased risk for the development of asthma (odds ratio, 2.58; 95% CI, 1.17-5.66; P = .018) after adjusting for age, sex, and smoking status. Individuals with asthma bearing the CT genotype of the C-509T polymorphism had significantly increased risk for severe airflow obstruction compared with individuals who had mild obstruction (odds ratio, 4.00; 95% CI, 1.06-15.08; P = .035). CONCLUSION: Our results indicate that the polymorphisms at C-509T and T869C of the TGF-beta(1) gene are associated with asthma susceptibility in atopic subjects of the Hong Kong Chinese population, and the C-509T polymorphism may play a role in the pathogenesis of airflow obstruction.     

Prevalence of diarrhea viruses in hospitalized children in Hong Kong in 2008

A total of 209 stool samples were collected from pediatric patients admitted for acute gastroenteritis in a hospital in Hong Kong, during an 8‐month period from January to August 2008, and were tested for the presence of rotavirus, norovirus, sapovirus, adenovirus, and astrovirus using a multiplex RT‐PCR assay. The most common virus was rotavirus group A (59 of 209, 28%, mainly serotypes G1, G2, G3, and G9), followed by norovirus group II (48 of 209, 23%), adenovirus (7 of 209, 3%, serotypes 2, 3, and 41), and sapovirus (2 of 209, 1%). Interestingly, none of the specimens in this study were positive for astrovirus. One sample was found to have a dual infection with both norovirus group II and adenovirus. The results support the importance of norovirus as a causative agent of diarrhea in children, which may be underestimated by the current routine diagnostic testing. J. Med. Virol. 81:1903–1911, 2009. © 2009 Wiley‐Liss, Inc.     

Declining asthma prevalence in Hong Kong Chinese schoolchildren

BACKGROUND: Many studies have reported an increase in the prevalence of asthma and related atopic disorders. The lack of standardized methodologies and 'objective' measurements make reliable comparison and monitoring of trends of asthma very difficult. METHODS: In this study, a total of 3321 schoolchildren aged 13-14 years were recruited for study using the Phase III Protocol of the International Study of Asthma and Allergic disease in Childhood (ISAAC). The results were compared with those obtained in the Phase I ISAAC study (1994-95), which used the identical and validated core questionnaires. RESULTS: The prevalence rates of physicians' diagnosis of asthma were similar in the two surveys (11.2% and 10.2%), but the prevalence rates of wheeze (written questionnaire) in the past year have decreased from 12.4% in 1994-95 to 8.7% in 2002 (P<0.001). For the video questionnaire, all asthmatic symptoms in the preceding 12 months were significantly lower in 2002 when compared with those in 1994-95. Among the subjects with diagnosed asthma, the prevalence rates of wheeze in the past 12 months (written questionnaire) has decreased from 39.1% to 27.6% (P<0.001). The prevalence rates of having wheezing attack at least once per month (video questionnaire) has decreased from 10.5% to 5.6% (P=0.013). CONCLUSION: Using the same standardized and validated ISAAC questionnaire, the prevalence rates of asthma symptoms in Hong Kong Chinese schoolchildren have decreased since 1994. The exact reasons for such trend remain to be explored.     

Immunohistological subtypes of non-Hodgkin's lymphoma in Hong Kong Chinese

One hundred and four unselected cases of non-Hodgkin's lymphoma (NHL) in adult Chinese patients in Hong Kong were typed, using monoclonal and conventional antibodies, by immunoenzymatic labelling methods on cryostat sections or cell smears. The total included 69 cases (66%) of B-cell and 26 (25%) of T-cell tumours. The diffuse large cell (centroblastic or immunoblastic) types formed the largest proportion (44.9%) of B lymphomas. Of 26 cases of T-cell lymphoma 25 were of peripheral type; of these 25, the most frequent subtype (42.3%) was the immunoblastic lymphadenopathy-like lesion. Although there were 9 pleomorphic T-cell lymphomas, none of the patients presented with the adult T-cell leukemia/lymphoma syndrome. The incidence of T-cell lymphomas in our population is not markedly higher than that of western countries, but there are some interesting differences in the types of T-cell lymphomas that are commonly seen.     

Sleep problems in Chinese elderly in Hong Kong.

BACKGROUND: To examine the sleep habits and one-year prevalence of sleep disturbance (difficulty in falling asleep, broken sleep and early morning wakening) as well as insomnia (subjectively inadequate or poor sleep) in an elderly Chinese population in Hong Kong. METHOD: In Phase 1, a representative sample of elderly aged 70 years or above were interviewed with a sleep questionnaire, and Cantonese versions of the Mini-Mental State Examination (CMMSE) and Geriatric Depression Scale(CGDS). In Phase 2, those with scores suggestive of cognitive impairment on CMMSE or depression on CGDS were interviewed by psychiatrists for making clinical diagnoses according to DSM IV. RESULTS: 1,034 elderly were interviewed in Phase 1. Occasional or persistent sleep disturbance were reported by 75% and insomnia in 38.2% of elderly. Slightly less than half of elderly with sleep disturbance complained of insomnia. Advancing age was associated with a higher rate of sleep disturbance while females had a higher rate of insomnia. Factors associated with sleep disturbance and insomnia included poor perceived health, past history of smoking, current depressive disorders, more chronic physical illness, more life events and more somatic complaints. Only 2.8% of the sample had taken sleeping pills within a one-year period. CONCLUSIONS: Sleep disturbance and insomnia are two separate but overlapping constructs and should be differentiated. Sleep disturbance is very common in the elderly and may be due to physiological changes with ageing. In contrast, those with a concommitant complaint of insomnia have impaired physical and mental health and may merit more medical attention.     

Report on anti-Dib encountered in two Hong Kong Chinese

Two cases of anti-Dib, a rarely encountered antibody, were identified in serum samples referred by hospital blood banks during the past 13 months. Case 1 is a 41-year-old female who required blood for elective surgery. Case 2 is a premature infant suffering from mild neonatal jaundice on day 2 after birth. The anti-Dib in both cases exhibited marked dosage effect. The titer/score against Di(a+b+) and Di(a-b+) red blood cells (RBCs) in case 1 was 8/10 and 32/32, respectively, and in case 2, 4/18 and 32/46. The monocyte monolayer assay (MMA) also gave a similar pattern of results, being l5 percent and 100 percent reactive when tested with Di(a+b+) and Di(a-b+) RBCs in case 1, and 0.4 percent (within normal range) and l4.4 percent in case 2. The patient in case 1 underwent her operation without blood transfusion. The infant in case 2 was treated by phototherapy and subsequently recovered without the need for exchange transfusion.     

Anorexia nervosa in Hong Kong: a Chinese perspective

A prospective study of sixteen Chinese anorexic patients in Hong Kong indicates that they were single young females who came from lower social class, exhibited severe self-induced weight loss, rigid maintenance of low body weight and amenorrhea. Weight reduction was primarily by dietary restriction. The typical bulimic syndrome and major depression were uncommon. There were multiple aetiological factors, but no pre-morbid obesity and little pressure to pursue slimness for beauty. Instead of displaying an intense fear of obesity and a distorted body image, patients more commonly attributed poor food intake to abdominal bloating. As such, they only partially fulfilled current criteria for diagnosis. It is argued that such clinical patterns arise logically from their sociocultural backgrounds, but may gradually change with Westernization.     

Amantadine therapy of epidemic influenza a(2) (Hong Kong)

In a double-blind comparison of the therapeutic effect of amantadine in a natural outbreak of Hong Kong influenza in January 1969 near Houston, Texas, the decrease in titers of virus in throat swabs from 12 treated patients during the first 10 hr of treatment was appreciably greater than similar titers of virus from 16 untreated patients (P = 0.06). The titer of shed virus decreased significantly more rapidly (P < 0.05) among amantadine-treated patients ill more than 48 hr before treatment than among five control patients who had been ill more than 48 hr. Cough, sore throat, and nasal obstruction cleared more rapidly in treated patients (P < 0.05), and decline of fever in 6 treated patients sick for less than 48 hr before treatment was more rapid than among 13 untreated patients who had been ill for less than 48 hr. These findings are considered to be consistent with a limited therapeutic effect of the drug.     

HLA class I allele distribution of a Hong Kong Chinese population based on high-resolution PCR-SSOP typing

A stem cell registry population from Hong Kong, of Chinese ethnicity, was examined for HLA-A and HLA-B alleles using a two-stage sequence-specific oligonucleotide probe system. Comparison of the HLA-A and HLA-B frequencies with different populations showed a close relationship with a Chinese population from Singapore, although there were several differences in the presence/absence of alleles at the HLA-B locus. Having the data available on these registry donors will influence the search strategy and the ongoing compilation of new donors to the registry. In addition, knowing which alleles do/do not occur in this population will aid in the distinction of ambiguities which result from the use of many of the typing kits available.