Original Article

Tan KBL, Yeo GSH
Correspondence: Dr George S H Yeo, mfm93b@pacific.net.sg

ABSTRACT
Introduction Turner syndrome is the most common sex chromosomal abnormality in female foetuses, and is associated with a high proportion of cardiac anomalies. The aim of this study was to look at the incidence, demographical data and epidemiological pattern of Turner syndrome in Singapore from 1999 to 2004 and to examine the birth defects associated with this condition, specifically with reference to cardiac defects.
Methods Data on Turner syndrome cases born in 1999–2004 were retrieved from the National Birth Defects Registry (NBDR) and analysed. Data on congenital cardiac defect cases notified to the NBDR in the same time period were also retrieved and compared with the Turner syndrome cases.
Results There were a total of 101 cases of Turner syndrome in the six-year period from 1999–2004, yielding an overall incidence of 0.85 per 1,000 female live births, or one in 1,180 female live births. The incidence was lowest among Indians (0.38 per 1,000) compared to Malays (0.72 per 1,000) and Chinese (0.90 per 1,000). 75 cases (74.3 percent) had the 45,X karyotype, while the other 26 cases (25.7 percent) were mosaics. The mean maternal age for 45, X was lower (32.2 years, range 22–42) compared to mosaics (34.5 years, range 27–40). 19.8 percent (20/101) were live births, 38.6 percent (39/101) were terminated pregnancies and 41.6 percent (42/101) were spontaneous miscarriages. 13.9 percent of Turner syndrome babies had cardiac defects compared to 1.2 percent in the general population (p-value is less than 0.0001). Major cardiac defects found among Turner syndrome babies compared to the general population included the coarctation of the aorta (5.9 percent compared to 0.03 percent, p-value is less than 0.0001), atrial septal defects (3.0 percent compared to 0.6 percent, p-value is 0.006), a hypoplastic left heart (2.0 percent compared to 0.05 percent, p-value is less than 0.0001), aortic hypoplasia (3.0 percent compared to 0.01 percent, p-value is less than 0.0001) and dextrocardia (1.0 percent compared to 0.02 percent, p-value is 0.0002).
Conclusion Cardiac defects, particularly left-sided ones, are significantly more common among Turner syndrome foetuses. The true incidence of this syndrome is likely to be higher than that quoted in this study, and can only be solved when a complete screening of an entire population has been performed.

Keywords: birth defects, cardiac defects, foetal defects, mosaicism, Turner syndrome
Singapore Med J 2009; 50(6): 587-590

Tan KBL, Fook-Chong SMC, Lee SL, Tan LK
Correspondence: Dr Kenny BL Tan, kennytan@nus.edu.sg

ABSTRACT
Introduction The aim of this study was to establish reference values of peak systolic blood flow velocity measurement in the foetal middle cerebral artery (MCA-PSV) in the local Asian obstetric population and to compare our reference ranges with those of previously-published studies.
Methods 329 normal pregnant women attending the outpatient antenatal clinics of the Department of Obstetrics and Gynaecology in the Singapore General Hospital underwent Doppler ultrasonography at least once between 16 and 40 weeks’ gestation. The blood flow velocity recordings from the foetal middle cerebral artery were obtained. New reference ranges were constructed by regressing each parameter on gestational age.
Results New reference ranges for foetal middle cerebral artery with gestation were constructed for an Asian population. Our reference curves were compared with that of a previously-constructed one.
Conclusion MCA-PSV increases with advancing gestational age. There appear to be differences between Asian and non-Asian reference ranges for MCA-PSV.

Keywords: anaemia, foetal anaemia, foetal middle cerebral artery, peak systolic blood flow velocity, prenatal ultrasonography
Singapore Med J 2009; 50(6): 584-586

Liang M, Lye DC, Chen MI, Chow A, Krishnan P, Seow E, Leo YS
Correspondence: Dr David C Lye, david_lye@ttsh.com.sg

ABSTRACT
Introduction Since late March 2009, a novel influenza H1N1 strain emerged in humans in Mexico and the United States. It has rapidly spread to many countries on different continents, prompting unprecedented activation of pandemic preparedness plans. Singapore has adopted a containment strategy with active screening of febrile travellers with respiratory symptoms from affected countries since April 27, 2009.
Methods All cases with new influenza A (H1N1) confirmed on polymerase chain reaction assay on combined nasal and throat swabs and who were admitted to the Communicable Disease Centre, were included in a prospective evaluation of clinical characteristics of new influenza A (H1N1).
Results From May 26 to June 3, 2009, there were ten patients with a mean age of 27.6 years, seven of whom were female. All but one travelled from the United States, six of whom travelled from New York; the last one travelled from the Philippines. Clinical illness developed within a mean of 1.4 days after arrival in Singapore, and presentation to the emergency department at a mean of 2.7 days from illness onset. Fever occurred in 90 percent, cough 70 percent, coryza 40 percent, sore throat and myalgia/arthralgia 30 percent; none had diarrhoea. The fever lasted a mean of 2.1 days. All were treated with oseltamivir. The clinical course was uncomplicated in all cases.
Conclusion Clinical features of new influenza A (H1N1) appeared mild, and ran an uncomplicated course in immunocompetent patients.

Keywords: containment, H1N1 virus, influenza A virus, pandemic, swine influenza
Singapore Med J 2009; 50(6): 581-583

Fong CB, Thong MK, Sam CK, Mohamed Noor MN, Ariffin R
Correspondence: Ms Fong Cheng Boon c/o Prof Thong Meow Keong, thongmk@um.edu.my

ABSTRACT
Introduction Rett syndrome (RS) is a severe neurodevelopmental disorder characterised by normal neurological development followed by progressive developmental regression. The X-linked dominant inheritance of RS has been mapped to the gene that encodes the methyl-CpG-binding protein-2 (MECP2) at Xq28. In the present study, denaturing high-performance liquid chromatography (DHPLC) was used to detect mutations in the MECP2 gene in 20 Malaysian RS patients.
Methods Polymerase chain reaction (PCR) was carried out to amplify the MECP2 coding exons 2, 3, and 4 in a total of eight reactions (exons 2, 3a, 3b, 4a, 4b, 4c, 4d and 4e). Subsequently, PCR products were analysed by DHPLC.
Results Mutations in the MECP2 gene were detected in 13 of the 20 (65 percent) RS patients. 11 patients had mutations in exons 3b and 4a and six patients had mutations in exon 4c. These mutations were mainly concentrated in the methyl-CpG-binding domain and the transcriptional-repression domain.
Conclusion Through the use of post-PCR high-performance liquid chromatography, 65 percent of 20 RS patients were found to have mutation(s) in the MECP2.

Keywords: denaturing high-performance liquid chromatography, MECP2 mutation, methyl-CpG-binding domain, mutation analysis, Rett syndrome, transcriptional-repression domain
Singapore Med J 2009; 50(5): 529-533

Ngeow WC, Aljunid ST
Correspondence: Dr Ngeow Wei Cheong, ngeowy@um.edu.my

ABSTRACT
Introduction This study was undertaken to establish the craniofacial anthropometric norms of young adult Malaysian Malays.
Methods The study group consisted of convenient samples of 100 healthy volunteers (aged 18–25 years), with an equal number of female and male subjects who had no history of mixed racial parentage. 22 linear measurements were taken twice from 22 landmarks over six craniofacial regions.
Results The Malays shared many similar sizes of measurements with the Singaporean Chinese. Their left eye fissure length and mouth width (ch-ch) were almost identical for both genders. However, Malay females had an upper lip height (sn-sto) (left) and ear width (pra-pa) similar to Singaporean Chinese females. Six other measurements, viz. the head width (eu-eu), head circumference (on-op), face height (n-gn), lower face height (sn-gn), (left) eye fissure height (ps-pi), cutaneous upper lip height (sn-ls) and cutaneous upper lip height (ls-sto), were 0.4–4.3 mm less in the Malays. Measurements for another four parameters, viz. the length of the head (g-op), biocular width (ex-ex), lower vermillion height (sto-li) and (left) ear length (sa-sba), were 0.5–3.6 mm higher in the Malays. Only three measurements were obviously different; the height of the head (v-n) and intercanthal width (en-en), were lower, and the protrusion of the nasal tip (sn-prn) was higher in the Malays.
Conclusion These findings suggest that three features, i.e. the height of the head (v-n), intercanthal width (en-en) and protrusion of the nasal tip (sn-prn) may be useful in differentiating a Malay face from a Singaporean Chinese one.

Keywords: anthropometry, craniofacial anthropometric norms, face, facial features
Singapore Med J 2009; 50(5): 525-528

Saleem MM
Correspondence: Dr Mohammad M Saleem, mohomari@hotmail.com

ABSTRACT
Introduction The aim of the study was to look into the feasibility, safety, efficacy and cost-effectiveness of utilising the remains of central venous catheters in infants from a developing country.
Methods Between June 2005 and December 2006, 96 neonates and infants with various illnesses and required the insertion of central venous access, were divided into two groups; those who required it for a short to medium term (44patients) received a piece of the remains of catheters, and those who required conventional catheter insertion intended for long-term use (52 patients) received a regular catheter. The same principle of insertion was used as for regular central venous access. The external jugular vein was used when possible or the internal jugular vein was used otherwise. After appropriate insertion, the catheter was mounted on an appropriately-sized cannula .A three-way stopcock connection was used to minimise manipulation of the cannula. Postoperative care was the same as for routine central venous lines. Complications encountered in the two groups were recorded and analysed.
Results Of the short- and medium-term catheters, 32 out of 44 patients (72.7 percent) completed the intended course of treatment successfully, and of the long-term catheters, 42 out of 52 patients (80.8 percent) completed the treatment successfully. Recorded complications were dislodgement, thrombosis and infection. These were, in the short-term group, as follows: five (11.4 percent), three (6.8 percent) and four (9.1 percent), respectively; and for the long-term group, two (3.8 percent), four (7.7 percent) and four (7.7 percent), respectively.
Conclusion Utilisation of the remains of venous catheters in properly-selected patients for short- and medium-term treatment is feasible, cost-effective and safe, and the rates of complications are comparable to cases with conventional catheter insertion.

Keywords: central venous catheter, modified central venous catheter, venous access
Singapore Med J 2009; 50(5): 522-524

Ngoo KS, Rohaizak M, Naqiyah I, Shahrun Niza AS
Correspondence: Prof Rohaizak Muhammad, rohaizak@hotmail.com

ABSTRACT
Introduction Breast cancer is a rare condition among men with a reported incidence of about one percent. Nevertheless, it is thought to behave similarly in both genders. Due to its rarity, male breast cancer is not widely reported, especially in the Asian population.
Methods In a five-year review of our breast cancer surgery series, about 1.6 percent involved male patients. There was a substantial delay in presentation among those men, whose mean age at presentation was 64 years.
Results The majority of patients presented with a painless lump. Histologically, all tumours were ductal in origin and all patients had lower than stage III malignancies. The majority of patients underwent mastectomy and axillary lymph node dissection. All male patients were commenced on adjuvant tamoxifen. The longest survival was 54 months with all patients remaining tumour-free.
Conclusion Malaysian men are at risk of breast cancer and seem to have a better prognosis.

Keywords: breast carcinoma, male breast carcinoma, male breast lump
Singapore Med J 2009; 50(5): 519-521

Ho CCK, Rohaizak M, Zulkifli SZ, Siti-Aishah MA, Nor-Aini U, Sharifah-Noor-Akmal SH
Correspondence: Dr Christopher Ho Chee Kong, chrisckho2002@yahoo.com

ABSTRACT
Introduction This study was conducted to determine the association between serum sex hormone levels and breast cancer.
Methods The study was conducted on newly-diagnosed breast cancer patients who had not received any treatment. Controls were women not known to have any breast disease or hormone-related tumours. Serum hormones were divided into quartiles. Logistic regression adjusting for age and race were done to calculate the odds ratio (OR) and 95 percent confidence interval (CI).
Results A total of 207 subjects were recruited; 73 premenopausal (37 cases, 36 controls) and 134 postmenopausal (68 cases and 66 controls) women. In the premenopausal women, only serum testosterone was positively associated with breast cancer (OR 1.72, 95 percent CI 0.40–7.40), but this was not a significant finding (p-value is 0.468). In the postmenopausal women, oestradiol, progesterone and testosterone were positively associated with breast cancer with a highest to lowest quartile OR of 1.48, 2.35 and 4.23 (95 percent CI 0.59–3.69, 1.11–4.95 and 1.52–11.78, respectively). The OR was significant for both progesterone and testosterone (p-values of 0.025 and 0.006, respectively).
Conclusion There were no statistically significant findings among the premenopausal cases. In postmenopausal women, serum progesterone and testosterone levels were significantly associated positively with the odds of having breast cancer.

Keywords: breast cancer, hormones, postmenopausal cancer risk, progesterone, sex hormones, testosterone
Singapore Med J 2009; 50(5): 513-518

Yadav SPS, Aggarwal N, Julaha M, Goel A
Correspondence: Dr Anuj Goel, dranujgoel@rediffmail.com

ABSTRACT
Introduction To date, myringoplasty conducted under the operating microscope has been found to have its limitations. With the introduction of the endoscope into other branches of surgery, there have been attempts at its utilisation in otology.
Methods Endoscope-assisted myringoplasty was carried out in 50 patients aged 18–45 years using the temporalis fascia graft. The middle ear was examined through perforation in order to exclude cholesteatoma.
Results The overall success rate of the graft uptake and improvement in conductive deafness as air-bone gap closure was achieved in 80 percent of cases.
Conclusion Endoscopic myringoplasty was found to be equally effective, less morbid and very cost-effective in small central perforations. However, it is not applicable in all cases, especially in those with large perforations.

Keywords: conductive deafness, endoscopic myringoplasty, myringoplasty, otoendoscopy, tympanoplasty
Singapore Med J 2009; 50(5): 510-512

Ngo SYA, Ong SHJ, Ponampalam R
Correspondence: Dr Adeline Ngo, gaensy@sgh.com.sg

ABSTRACT
Introduction Stonefish, belonging to the genus Synanceia and classified under the Synanceiidae family, are commonly found in the shallow waters of the Indo-Pacific region and are considered the most dangerous and venomous of this family. The aim of the study was to describe the presenting features, clinical course and current management of this series of patients with stonefish envenomation presenting to a tertiary general hospital in Singapore.
Methods Data involving stonefish stings was retrospectively retrieved from the Singapore General Hospital Accident & Emergency Emerge Version 3.7.6 database from October 2004 to September 2006. Information, such as the patients’ demographics, date and location of the incident, identity of the fish, local or systemic effects, pain score (upon arrival and after treatment), investigations and treatment as well as the outcome of the patients, were evaluated.
Results 30 cases were identified. The median age of the patients was 28 years. The majority of patients were male (80 percent) and 47 percent of cases were foreign nationals. Most incidences occurred on weekends/public holidays(77percent), with November having the highest number of cases (seven cases). The majority of cases (80 percent) arrived at the hospital within two hours of envenomation. Symptoms included extreme pain, swelling and redness of the affected limbs. 24 (80 percent) patients received hot water soak treatment and 27 (90 percent) patients received either intramuscular pethidine or diclofenac for analgesia, where nine patients (33 percent) required additional analgesics after a period of observation. 17 patients (58 percent) were treated and discharged, eight (26 percent) were referred to a specialist for follow-up and five (16 percent) were admitted for an average of three days. 13 out of 25 patients (52 percent) were discharged with antibiotics. One case complained of persistent pain and hyperalgesia five months post-envenomation. One patient required surgical intervention. No deaths and systemic symptoms were reported.
Conclusion Cases of stonefish envenomation that presented to our hospital showed that the majority of patients were young male adults. Stonefish envenomation, though it rarely kills, can cause extreme pain, swelling and erythema, which can be managed with symptomatic treatment.

Keywords: bites, fish venom, poisoning, stings, stonefish envenomation, stonustoxin, Synanceia horrida, Synanceiidae
Singapore Med J 2009; 50(5): 506-509