Early pituitary-adrenal response and respiratory outcomes in preterm infants

OBJECTIVE

To assess the influence of circulating (basal) and stimulated plasma adrenocorticotrophin (ACTH) and serum cortisol on the duration of oxygen supplementation and development of chronic lung disease (CLD) in preterm, very low birthweight infants.

METHODS

A total of 226 human corticotrophin releasing hormone stimulation tests were performed on 137 very low birthweight infants on days 7 and 14 in a tertiary neonatal centre.

RESULTS

Multivariate regression analysis showed that the duration of oxygen supplementation was negatively associated with birth weight, but positively associated with alveolar-arterial oxygen gradient (A-aDO(2)) on the first day and with basal serum cortisol on day 14. In addition, the multivariate classification and regression trees model indicated that the two most useful indices for predicting CLD were clinical risk index for babies (CRIB) score (> 9) and peak serum cortisol (> 740 nmol/l) on day 14. The sensitivity, specificity, positive and negative predictive values of these factors for predicting CLD were 53%, 80%, 81%, and 70% respectively.

CONCLUSIONS

The findings suggest that birth weight, severity of initial respiratory failure as reflected by the A-aDO(2) gradient, and continuing "stress" with persistent increase in serum cortisol on day 14 are significant risk factors associated with the duration of oxygen supplementation, whereas early pituitary-adrenal response (basal and peak plasma ACTH and serum cortisol on day 7) is not an independent risk factor. Although CRIB score in combination with peak serum cortisol on day 14 are useful predictors of CLD, the need to use a stimulation test and the relatively late timing of the forecast render these indices unattractive for routine clinical use.

Risk factors and clinical consequences of human herpesvirus 7 infection in paediatric haematopoietic stem cell transplant recipients

Human herpesvirus 7 (HHV-7) is the least studied beta-herpesvirus in transplant settings. This prospective study examined the activity of HHV-7 during the first 12 weeks post-stem cell transplant in 59 paediatric patients. The presence of HHV-7, human cytomegalovirus (HCMV) and human herpesvirus 6 (HHV-6) in blood was monitored weekly by a multiplex nested polymerase chain reaction. Overall, 33 (55.9%) patients had one or more surveillance blood sample(s) positive for HHV-7. In contrast to HCMV and HHV-6, no obvious peak time of reactivation was observed for HHV-7. The occurrence of HHV-7 DNAaemia showed a significant negative association with HHV-6 (P=0.022), but with no association with HCMV. A significant higher positive rate for HHV-7 was found in autologous versus allogeneic (P=0.002), and in peripheral blood versus umbilical cord/marrow (P<0.001) transplant. Acyclovir had no effect, whereas ganciclovir was associated with a lower rate of HHV-7 reactivation (P=0.009). One patient died of HHV-7 associated brain stem encephalitis. The administration of colony stimulating factor, occurrence of acute graft versus host disease, time to neutrophil and platelet engraftment showed no significant association with the occurrence of HHV-7 DNAaemia.

Auricular anthropometry of Hong Kong Chinese babies

OBJECTIVES

To provide a database of the auricular measurements of Chinese infants born in Hong Kong.

DESIGN

Prospective cross-sectional study.

SETTING AND SAMPLE POPULATION

A total of 2384 healthy singleton, born consecutively at the Prince of Wales Hospital and the Union Hospital from October 1998 to September 2000, were included in the study. The range of gestation was 33-42 weeks.

MEASUREMENTS AND RESULTS

Measurements included ear width (EW), ear length (EL) and ear position (EP). The data show generally higher values for males in the parameters measured. When compared with previously published data for Caucasian and Jordanian term babies, Chinese babies have shorter EL. The ears were within normal position in nearly all our infants.

CONCLUSION

The human ear appears to grow in a remarkably constant fashion. This study establishes the first set of gestational age-specific standard of the ear parameters for Chinese new-borns, potentially enabling early syndromal diagnosis. There are significant inter-racial differences in these ear parameters.

Severe acute respiratory syndrome: 'SARS' or 'not SARS'

Accurate clinical diagnosis of severe acute respiratory syndrome (SARS) based on the current World Health Organization definition is difficult and at times impossible at the early stage of the disease. Both false positive and false negative cases are commonly encountered and this could have far-reaching detrimental effects on the patients, their family and the clinicians alike. Contact history is particularly important in diagnosing SARS in children as their presenting features are often non-specific. The difficulty in making a correct diagnosis is further compounded by the lack of a sensitive rapid diagnostic test. Serology is not particularly helpful in the initial triaging of patients as it takes at least 3 weeks to become positive. Co-infection and other treatable conditions should not be missed and conventional antibiotics should remain as part of the first-line treatment regimen. We report five cases to illustrate the difficulties and dilemmas faced by clinicians in diagnosing SARS in children.

Risk factors for childhood overweight in 6- to 7-y-old Hong Kong children

OBJECTIVE

To identify risk factors for overweight in Hong Kong children aged 6-7 y.

DESIGN

Case-control study.

SETTING

Student Health Service Centres, Hong Kong.

SUBJECTS

A total of 343 Hong Kong Chinese children aged 6-7 y old categorised into three groups, an overweight group (> or =92 nd centile for BMI), a normal middle-weight group (45th-55th centile for BMI) and a normal low-weight group (< or =8th centile for BMI).

MEASUREMENTS

Subjects and their parents/caregivers were interviewed at home. Data on lifestyle habits, dietary habits, family structure and demographic background were collected by questionnaire. A 3-day dietary record was administrated by the parents/caregivers to assess dietary intake of the children.

RESULTS

Logistic regression analyses (overweight group compared with middle-weight plus low-weight groups) showed that childhood overweight was significantly associated with parental obesity (BMI > or =25 kg/m(2), Asian reference) (paternal: OR=2.66, 95% CI=1.51-4.70; maternal: 5.07, 2.62-9.79) but not parental overweight (BMI=23-25 kg/m(2)). After adjustment for parental obesity, the odds ratio for childhood overweight was increased by birth weight (<3.0 kg as reference, 3.0-3.5 kg: 2.13, 1.18-3.84; > or =3.5 kg: 4.89, 2.49-9.60) and decreased by sleeping duration (<9 h/day as reference, 9-11 h/day: 0.54, 0.30-0.97; > or =11 h/day: 0.31, 0.11-0.87). Childhood overweight was also significantly associated with higher energy consumption (2.62, 1.20-5.74) and having a father who was a current smoker (2.08, 1.25-3.46).

CONCLUSIONS

Although healthy diet and regular exercise will remain the cornerstones of obesity management in children, our data support the view that education about maintaining a healthy weight could be introduced much earlier in those families with high-risk children, as indicated by high parental BMI or high birth weight. The utility and practicality of such an approach should be carefully evaluated before becoming part of any public health policy. Further study of the role of short sleeping duration and parental smoking on childhood obesity development is warranted.

Consensus statement on iodine deficiency disorders in Hong Kong

This article reviews the available data on the study of iodine deficiency disorders in Hong Kong and to discuss the approach towards preventing such disorders in Hong Kong. The importance of iodine and iodine deficiency disorders is described, and the available data on the dietary iodine intake and urinary iodine concentration in different populations of Hong Kong are summarised and discussed. Dietary iodine insufficiency among pregnant women in Hong Kong is associated with maternal goitrogenesis and hypothyroxinaemia as well as neonatal hypothyroidism. Borderline iodine deficiency exists in the expectant mothers in Hong Kong. Women of reproductive age, and pregnant and lactating women should be made aware and educated to have an adequate iodine intake, such as iodised salt, as an interim measure. A steering group involving all stakeholders should be formed to advise on the strategy of ensuring adequate iodine intake, including universal iodisation of salt in Hong Kong. Continuous surveillance of iodine status in the Hong Kong population is necessary.

A controlled study of sleep related disordered breathing in obese children

BACKGROUND

Unlike the adult sleep related disordered breathing (SDB) patients who are typically obese, the relation between obesity and childhood SDB is not clear.

AIMS

To investigate whether obese children are more at risk of obstructive SDB when compared to normal population, and whether this risk is potentiated by the presence of pharyngeal lymphoid tissue.

METHODS

Forty six obese children (age 10.8 (SD 2.3) years; BMI 27.4 (SD 5.1)), and 44 sex and age matched normal weight children (age 11.7 (SD 2.1) years; BMI 18 (SD 1.8)) were studied. All children underwent a set of physical examinations (including the upper airways) and sleep studies.

RESULTS

The obese children were different from the normal weight children in terms of type (predominantly obstructive), frequency, and severity of respiratory disturbances. Depending on the criteria used, 26% or 32.6% of obese children had SDB; 2.3% of normal controls had OAI > or =1 and 4.5% had RDI > or =5. Presence of SDB was related to presence of tonsils (size >2; range 0-4) (OR 12.67, 95% CI 2.14 to 75.17) and BMI (OR 1.20, 95% CI 1.08 to 1.33).

CONCLUSIONS

Results suggest that obese children are at increased risk of obstructive SDB; the presence of any pharyngeal lymphoid tissue enlargement in obese children should therefore be aggressively managed.

Severe acute respiratory syndrome (SARS) in children: epidemiology, presentation and management

Severe acute respiratory syndrome (SARS) is a newly recognised and highly contagious respiratory infection caused by a new strain of coronavirus. The disease can result in progressive respiratory failure in adults and the mortality rate has been reported to be 8-15%. This infection spreads by droplet transmission and children appear to acquire SARS through close household contact exposure to infected adults. Disease severity is, however, much milder in the paediatric age group. The common laboratory findings in infected children and adolescents include lymphopaenia and elevated levels of lactate dehydrogenase and creatinine phosphokinase. Air space consolidation is commonly seen during the course of the illness although chest radiographs are normal on presentation in half of the cases. The pathophysiology of SARS appears to be related to immunological dysregulation in response to the coronavirus infection. The optimal treatment of SARS in children remains to be determined. No case fatality in infected children has been reported. The early and proper isolation of infected adults, meticulous infection control measures in the hospital setting, exhaustive contact tracing and quarantine measures are important steps in preventing the spread of the disease among health care workers and into the community. The development of a sensitive and rapid test for early diagnosis is underway. Further controlled trials are necessary to define the optimal treatment of this infection in children.

Imaging in severe acute respiratory syndrome (SARS)

Severe acute respiratory syndrome (SARS) is a highly infectious disease caused by a novel coronavirus, and has become pandemic within a short period of time. Imaging plays an important role in the diagnosis, management and follow-up of patients with SARS. The current status of imaging in SARS is presented in this review.

Sleeping energy expenditure in paediatric patients with obstructive sleep apnoea syndrome

OBJECTIVE

To investigate sleeping energy expenditure in paediatric patients with obstructive sleep apnoea syndrome.

DESIGN

Retrospective study. Setting. University teaching hospital, Hong Kong.

PATIENTS AND METHODS

A retrospective analysis comparing sleeping energy expenditure in patients with confirmed obstructive sleep apnoea syndrome and control subjects matched for age, sex, and ideal weight for body height. Subjects were recruited from the Paediatric Chest Clinic and all had undergone overnight polysomnography and sleeping energy expenditure measurement by open-circuit indirect calorimetry using a metabolic cart and canopy system. The measurements were taken during slow-wave sleep.

RESULTS

Twenty-four cases with obstructive sleep apnoea syndrome (apnoea hypopnoea index >5) and 23 control subjects were studied. Mean age and ideal weight for body height were 9.4 (standard deviation, 3.9) years and 152.5% (27.2%), respectively. Mean sleeping energy expenditure corrected for body weight for the cases and the control group were 44.83 (standard deviation, 10.49) Kcal/day and 40.71 (10.60) Kcal/day, respectively. Sleeping energy expenditure was not found to be associated with the severity of obstructive sleep apnoea syndrome (r=0.34, P=0.27).

CONCLUSION

A trend towards greater sleeping energy expenditure was found in patients with obstructive sleep apnoea syndrome. Further studies on the metabolic aspects of this condition are required.

Hurler's syndrome with cor pulmonale secondary to obstructive sleep apnoea treated by continuous positive airway pressure

A 6-year-old boy with Hurler's syndrome presented with right heart failure and pulmonary hypertension secondary to severe obstructive sleep apnoea. Both his sleep apnoea and cor pulmonale were effectively controlled with continuous positive airway pressure therapy.

Infection control for SARS in a tertiary neonatal centre

The Severe Acute Respiratory Syndrome (SARS) is a newly discovered infectious disease caused by a novel coronavirus, which can readily spread in the healthcare setting. A recent community outbreak in Hong Kong infected a significant number of pregnant women who subsequently required emergency caesarean section for deteriorating maternal condition and respiratory failure. As no neonatal clinician has any experience in looking after these high risk infants, stringent infection control measures for prevention of cross infection between patients and staff are important to safeguard the wellbeing of the work force and to avoid nosocomial spread of SARS within the neonatal unit. This article describes the infection control and patient triage policy of the neonatal unit at the Prince of Wales Hospital, Hong Kong. We hope this information is useful in helping other units to formulate their own infection control plans according to their own unit configuration and clinical needs.

Sociodemographic and atopic factors affecting breastfeeding intention in Chinese mothers

OBJECTIVE

The factors accounting for the low 'ever breastfeeding' rate in Hong Kong remain unclear. The objective of this survey was to study the intention and planned duration of breastfeeding in Chinese women in Hong Kong, and to investigate the sociodemographic and atopic factors affecting the intention to breastfeed.

METHODS

All Chinese mothers who were Hong Kong residents and who delivered their babies in a University teaching hospital were given a self administered and anonymous Chinese questionnaire within 1 day postpartum. The questionnaire included items on sociodemographic data, the presence of allergic diseases in the families, and the intention and planned duration of breastfeeding for their newborn babies.

RESULTS

A total of 1374 eligible questionnaires were collected. About one-third of mothers were born outside Hong Kong and the majority (78%) of them were aged between 25 and 40 years. Logistic regression revealed that only socioeconomic factors, namely older maternal age (odds ratio (OR) 2.10, 95% confidence interval (CI) 1.14-3.89), parity (OR 3.08, 95% CI 1.02-9.27) and higher educational background (OR 2.87, 95% CI 1.92-4.27), significantly affected the intention to breastfeed. In addition, mothers born outside Hong Kong and those with first babies, had a longer intended duration of breastfeeding (P-values < 0.001 and 0.033, respectively). A family history of atopic disorders in parents or siblings did not influence the breastfeeding intention of these Chinese mothers.

CONCLUSION

Several sociodemographic factors, rather than a history of atopic disorders, of Chinese mothers in Hong Kong affected their intention to breastfeed and the planned duration of breastfeeding.

Facial anthropometry of Hong Kong Chinese babies

OBJECTIVES

To provide a database of the craniofacial measurements of Chinese infants born in Hong Kong.

DESIGN

Prospective cross-sectional study.

SETTING AND SAMPLE POPULATION

A total of 2371 healthy singleton, born consecutively at the Prince of Wales Hospital and the Union Hospital from June 1998 to June 2000, were included in the study. The range of gestation was 33-42 weeks.

MEASUREMENTS AND RESULTS

Measurements included facial width (FW), facial height (FH), nasal length (NL), nasal width (NW), and length of the philtrum (PhilL). The facial, nasal, nasofacial and nasozygomatic indices were derived. The data show generally higher values for males in the parameters measured. The various indices remained remarkably constant and did not vary significantly between the two genders or with gestation. When compared with previously published data for white people term babies, Chinese babies have similar NW but shorter philtrum length.

CONCLUSION

The human face appears to grow in a remarkably constant fashion as defined by the various indices of facial proportions. This study establishes the first set of gestational age-specific standard of such craniofacial parameters for Chinese new-borns, potentially enabling early syndromal diagnosis. There are significant inter-racial differences in these craniofacial parameters.

[Individual allergens as risk factors for asthma and bronchial hyperresponsiveness in Chinese children]

OBJECTIVE This study aimed to determine the relationship between individual allergens with current wheezing and bronchial hyperresponsiveness (BHR) in schoolchildren from three chinese cities: Beijing, Guangzhou and Hong Kong. METHODS Community-based random samples of 10-yr-old schoolchildren from the 3 cities were recruited for study using the International Study of Asthma and Allergies in Childhood (ISAAC) Phase II protocol. The subjects were studied by parental questionnaires (n = 10,902), skin-prick tests (n = 3478), and methacholine challenge tests (n = 608). RESULTS The highest prevalence rates of wheezing in the past 12 months (Beijing, 3.8%; Guangzhou, 3.4%; Hong Kong, 5.8%) and atopy (Beijing, 23.9%; Guangzhou, 30.8%; Hong Kong, 41.2%, defined as having <or= 1 positive skin-prick tests,) were seen in schoolchildren from Hong Kong. The highest prevalence rates of BHR (Beijing, 33.2%; Guangzhou, 45.8%; Hong Kong, 30.7%) were seen in schoolchildren from Guangzhou. Multivariate-logistic regression analyses revealed that sensitization to Dermatophagoides pteronyssinus [odds ratio ((OR)) = 4.48; 95% confidence interval ((CI)); 3.02-6.66], cat ((OR) 2.85; 95% (CI) 1.24-6.50), Dermatophagoides farinae (DF) ((OR) 2.41, 95% (CI) 1.65-3.51) and Mixed grass pollen ((OR) 2.85, 95% (CI) 1.24-6.50) were significantly associate with current wheezing atopy ((OR) 1.29, 95% (CI) 0.74-2.24), was not an independent risk factor for current wheezing in children from any of the three cities. Furthermore, atopy ((OR) 2.53, 95% (CI) 1.93-6.97) were significantly associated with BHR. CONCLUSION The authors confirmed that sensitization to house dust mite and cat was significantly associated with current wheezing and bronchial hyperresponsiveness in Chinese schoolchildren.

Clinical presentations and outcome of severe acute respiratory syndrome in children

Hong Kong has been severely affected by severe acute respiratory syndrome (SARS). Contact in households and health-care settings is thought to be important for transmission, putting children at particular risk. Most data so far, however, have been for adults. We prospectively followed up the first ten children with SARS managed during the early phase of the epidemic in Hong Kong. All the children had been in close contact with infected adults. Persistent fever, cough, progressive radiographic changes of chest and lymphopenia were noted in all patients. The children were treated with high-dose ribavirin, oral prednisolone, or intravenous methylprednisolone, with no short-term adverse effects. Four teenagers required oxygen therapy and two needed assisted ventilation. None of the younger children required oxygen supplementation. Compared with adults and teenagers, SARS seems to have a less aggressive clinical course in younger children.

Updated gestational age specific birth weight, crown-heel length, and head circumference of Chinese newborns

OBJECTIVE

To construct gestation specific standards of birth weight, crown-heel length, and head circumference of Chinese infants.

DESIGN

A prospective cross sectional population study.

METHODS

The birth weight, crown-heel length, and head circumference were prospectively measured using standard equipment in newborns delivered at 24-42 weeks gestation in the maternity units of 10 public hospitals and two private hospitals in Hong Kong. The findings were used to construct gestation specific standards of these variables. The LMS method using maximum penalised likelihood was used to perform model fitting. The results were compared with those obtained from a cohort of infants born in the same locality between 1982 and 1986.

RESULTS

From October 1998 to September 2000, a total of 10 032 infants were measured, representing 9.6% of the total deliveries in Hong Kong during that period. An extra 307 infants with gestation < or = 35 weeks were recruited from October 2000 to June 2001. Each of the three variables showed a normal distribution at each gestational week. Gestation specific reference standards for each variable were constructed for male and female infants separately. Comparison with the 1982-1986 cohort showed a significant secular trend to increased birth weight. The trend was small, but significant, for crown-heel length and head circumference.

CONCLUSION

These growth standards will provide useful references for the care of newborns of ethnic Chinese origin. These standards, especially that for birth weight, should be updated regularly.

Proinflammatory and anti-inflammatory cytokine responses in preterm infants with systemic infections

OBJECTIVE

A prospective study to investigate the pattern of proinflammatory and anti-inflammatory cytokine responses in preterm infants with systemic infection.

METHODS

Very low birthweight infants in whom infection was suspected when they were > 72 hours of age were eligible. A full sepsis screen was performed in each episode. Key cytokines of both proinflammatory and anti-inflammatory pathways, including interleukin (IL) 2, IL4, IL5, IL6, IL10, interferon (IFN) gamma, and tumour necrosis factor (TNF) alpha, were measured at 0 (at the time of sepsis evaluation), 24, and 48 hours by flow cytometric analysis or immunoassay.

RESULTS

Thirty seven of the 127 episodes of suspected clinical sepsis were proven infection or necrotising enterocolitis. Both proinflammatory (IL2, IL6, IFNgamma, TNFalpha) and anti-inflammatory (IL4, IL10) cytokines were significantly increased in infected infants compared with non-infected infants. Significant correlations were observed between IL6 and TNFalpha or IL10 as well as IL10 and IFNgamma in infected infants. In the subgroup analysis, plasma IL6, IL10, and TNFalpha concentrations, and IL10/TNFalpha and IL6/IL10 ratios were significantly elevated in patients with disseminated intravascular coagulation compared with infected infants without. The IL10/TNFalpha ratios had decreased significantly 48 hours after the onset, whereas the IL6/IL10 ratio showed only a non-significant decreasing trend. Further, the IL6/IL10 ratio in the deceased infant was disproportionally increased at presentation and continued to increase despite treatment.

CONCLUSION

The results indicate that the counter-regulatory mechanism between the proinflammatory and anti-inflammatory cytokine pathways is probably operational in preterm infants of early gestation. High plasma IL6, IL10, and TNFalpha concentrations, and IL10/TNFalpha and IL6/IL10 ratios signify severe infection, but transiently elevated plasma IL10 concentration or IL10/TNFalpha ratio does not necessarily indicate a poor prognosis.

Plasma TARC concentration may be a useful marker for asthmatic exacerbation in children

Recent studies suggested the T-helper cells type-2 lymphocytes-specific thymus and activation-regulated chemokine (TARC) and monocyte-derived chemokine (MDC) are useful inflammatory markers for chronic asthma. However, their roles in assessing the severity of acute asthma are unknown. This study aims to evaluate the serial changes of plasma TARC and MDC concentrations in children with asthmatic exacerbation. All patients with acute asthma were treated with systemic corticosteroid for 5 days. The severity of asthmatic exacerbation was classified according to the Global Initiative for Asthma guidelines. Plasma TARC and MDC concentrations were measured by sandwich enzyme immunoassays. Sixteen children, with a median (interquartile range) age of 9.3 (7.2-10.6) yrs and asthmatic exacerbation, were recruited. Plasma TARC concentration showed inverse correlation with peak expiratory flow rate at presentation. The median plasma TARC concentration was highest during the acute attacks (46 pg x mL(-1)) as compared to those levels at 1 (31 pg x mL(-1)) and 5 weeks (32 pg x mL(-1)) following treatment. The median plasma MDC level similarly decreased from 698 pg x mL(-1) at baseline to 261 pg x mL(-1) 1 week later, but increased back to 574 pg x mL(-1) at 5 weeks. These results suggest that plasma T-helper cells type-2 lymphocytes-specific thymus and activation-regulated chemokine but not monocyte-derived chemokine concentration may be a useful inflammatory marker in assessing asthmatic exacerbation in children.

Anti B cell targeted immunotherapy for treatment of refractory autoimmune haemolytic anaemia in a young infant

We report the case of an 8 week old infant with fulminant autoimmune haemolytic anaemia refractory to conventional immunomodulating treatment. Massive haemolysis resulted in cardiac decompensation and acute renal failure which necessitated mechanical ventilation and peritoneal dialysis. Rituximab, a chimeric anti-CD20 monoclonal antibody, halted progression of the haemolytic process, but the patient died of acute viral pneumonia and disseminated fungal infection. Earlier introduction of rituximab might have prevented the renal complications. Paediatricians should be aware of this useful therapeutic tool for treatment of refractory autoimmune haemolytic anaemia and balance its use against the risk of potential life threatening infection.

The effects of obesity on pulmonary function

AIMS

(1) To determine the predominant pulmonary function abnormality in our population of obese children; and (2) to assess the correlation between the severity of lung function impairment and the degree of obesity as assessed by dual energy x ray absorptiometry (DEXA).

METHODS

Sixty four obese patients underwent physical examination, standardised pulmonary function tests (spirometry, lung volumes, and single breath diffusion capacity for carbon monoxide), and DEXA scan measurements. The trunk and subtotal (total - head) body fat mass were used as surrogate index of body adiposity.

RESULTS

Sixteen girls and 48 boys with median age and body mass index (BMI) of 12 years (interquartile range (IQR): 10-14) and 30.1 kg/m2 (IQR: 27.2-32.8) respectively were studied. None of the patients had clinical evidence of cardiopulmonary disease. Reduction in functional residual capacity (median FRC 93% predicted, IQR: 68.5-116.5%) and impairment of diffusion capacity (median DLco 83.5% predicted, IQR: 70.0-100.7%) were the most common abnormalities in our cohort, being observed in 30 (46%) and 21 (33%) patients respectively. Obstructive ventilatory impairment was found in three patients. There was significant negative correlation between the degree of reduction of FRC but not DLco with DEXA scan measurements, but such a relation was not found when BMI was used as the indicator of obesity.

CONCLUSION

Reduction in FRC and diffusion impairment were the commonest abnormalities found in our cohort of obese patients. Reduction in static lung volume was correlated with the degree of obesity.

A genomic approach to mutation analysis of holocarboxylase synthetase gene in three Chinese patients with late-onset holocarboxylase synthetase deficiency

OBJECTIVE

Multiple carboxylase deficiency (MCD, MIM:253270) is a common organic aciduria and caused by deficiency of either biotinidase or holocarboxylase synthetase (HLCS; EC 6.3.4.10). Patients commonly present during early infancy with acute metabolic derangements and severe metabolic acidosis. Recently, a late onset form of HLCS deficiency was also described. The different phenotypes (early and late presenting) may be related to a spectrum of mutations in HLCS gene. Applications of mutation analysis in HLCS had been limited previously by the requirement of cDNA from living tissue for study. We described here a genomic approach for molecular diagnosis of HLCS deficiency which we have used to detect mutations in Chinese patients who had the late-onset form of HLCS deficiency. In addition, a fibroblast cell line with MCD from Coriell Cell repositories was also studied.

DESIGN AND METHODS

Three Chinese patients with late onset HLCS deficiency were studied. The genomic sequence of HLCS was retrieved and newly designed primers were used to cover all coding sequences of the gene. PCR products were analyzed by direct sequencing. Population allelic frequencies of mutations detected were determined by genotyping of control samples by restriction fragment length polymorphism.

RESULTS

We found a recurrent mutation, R508W, in the three unrelated Chinese patients. Two were homozygous for this mutation. The other patient was a compound heterozygote of R508W and a novel mutation, D634N. The results suggest that R508W may be an important and relatively prevalent disease-causing mutation in Chinese MCD patients. A fibroblast cell-line from an African patient revealed an additional novel mutation, R565X and a known mutation, V550M.

CONCLUSION

R508W is a recurrent mutation in Chinese MCD patients which is associated with the late onset phenotype. This new genomic approach for mutation analysis of HLCS gene provides new opportunities in studies of MCD.

Craniofacial anthropometry of Hong Kong Chinese babies: the eye

OBJECTIVES

To provide a database of the canthal measurements of Chinese infants born in Hong Kong.

DESIGN

Prospective cross-sectional study.

SETTING AND SAMPLE POPULATION

A total of 2,371 healthy singleton, born consecutively at the Prince of Wales Hospital and the Union Hospital from June 1998 to June 2000, were included in the study. The range of gestation was 33-42 weeks.

MEASUREMENTS AND RESULTS

Canthal parameters were measured and included the outer canthal distance (OCD), intercanthal distance (ICD) and palpebral fissure length (PFL). The data generally show higher values for males in the parameters measured. The measurements were also compared with data published overseas. PFL and OCD were significantly larger in Hong Kong Chinese newborn babies, whereas ICD was smaller.

CONCLUSION

This study establishes the first set of gestational age-specific standard of such craniofacial parameters for Chinese newborn babies, potentially enabling early syndromal diagnosis. There are significant inter-racial differences in these canthal parameters.