An Unusual Hydrops Fetalis Associated with Compound Heterozygosity for Krüppel-like Factor 1 mutations

Hydrops fetalis is commonly due to Hb Bart's (γ4) disease in South East Asia. Here, we report an unusual case of hydrops fetalis due to congenital dyserythropoietic anemia (CDA) associated with compound heterozygosity for Krüppel-like factor 1 (KLF1) gene mutations. Fetal cardiomegaly was first detected on routine mid-trimester scan in a pregnant woman with normal mean corpuscular volume (MCV) and Rhesus positive status. The fetus subsequently developed hydrops fetalis, and cordocentesis showed severe fetal anemia with a hemoglobin (Hb) level of 3.4 g/dL. Common causes of fetal anemia including Hb Bart's disease, parvovirus infection, and red cell antibodies were excluded. In view of the marked increase in erythroblasts at various stages of erythropoiesis, the diagnosis of CDA was suspected. We screened the couple for previously reported KLF1 gene mutations, showing that the mother was heterozygous for the c.525_526insCGGCGCC, p.Gly176Argfs*179 mutation, and her husband heterozygous for c.1012C>A, p.Pro338Thr mutation. The fetus was a compound heterozygote for these two KLF1 mutations. After counseling, repeated intrauterine transfusions were given at 27, 29, and 34 weeks' gestation; the hydrops fetalis was resolved. The baby was delivered at 34 weeks' gestation and required monthly blood transfusions but was otherwise thriving. Bone marrow aspiration at 10 months of age showed the features of ineffective erythropoiesis, compatible with CDA. In conclusion, hydrops fetalis can rarely be due to CDA associated with a compound heterozygous mutation for KLF1 gene mutations, and be managed by repeated intrauterine transfusions. Our present report adds to the wide clinical spectrum of KLF1 mutations.

Effect of non-invasive prenatal testing as a contingent approach on the indications for invasive prenatal diagnosis and prenatal detection rate of Down's syndrome

INTRODUCTION

In Hong Kong, universal combined first-trimester screening for Down's syndrome was started as a 'free service' in July 2010. Non-invasive prenatal testing was available as a self-financed item in August 2011. This study aimed to determine whether the introduction of non-invasive prenatal testing as a contingent approach influenced the indications for invasive prenatal diagnosis and the consequent prenatal detection of Down's syndrome.

METHODS

This historical cohort study was conducted at the Prenatal Diagnosis Clinic of Queen Elizabeth Hospital in Hong Kong. We compared the indications for invasive prenatal diagnosis and prenatal detection of Down's syndrome in singleton pregnancies 1 year before and 2 years following the availability of non-invasive prenatal testing as a contingent test after a positive aneuploidy test. All pregnant women who attended our hospital for counselling about universal Down's syndrome screening between August 2010 and July 2013 were recruited.

RESULTS

A total of 16 098 women were counselled. After the introduction of non-invasive prenatal testing, the invasive prenatal diagnosis rate for a positive aneuploidy screening reduced from 77.7% in 2010-11 to 68.8% in 2012-13. The new combined conventional plus non-invasive prenatal testing strategy was associated with a lower false-positive rate (6.9% in 2010-11 vs 5.2% in 2011-12 and 4.9% in 2012-13). There was no significant increase in invasive prenatal diagnosis for structural anomalies over the years. There was no significant trend in the overall prenatal detection rate of Down's syndrome (100% 1 year before vs 89.1% 2 years after introduction of non-invasive prenatal testing). Four (2.6%) of 156 women who underwent non-invasive prenatal testing for a screen-positive result had a high-risk result for trisomy 21, which was subsequently confirmed by invasive prenatal diagnosis. There were no false-negative cases.

CONCLUSION

The introduction of non-invasive prenatal testing as a contingent approach reduced the invasive prenatal diagnosis rate for a positive aneuploidy screening without affecting the invasive prenatal diagnosis rate for structural anomalies or the overall detection rate of fetal Down's syndrome.

Two unusual cases of haemoglobin Bart's hydrops fetalis due to uniparental disomy or non-paternity

The authors present 2 unusual cases of haemoglobin (Hb) Bart's hydrops fetalis and highlight the problem of a screening system for α-thalassaemia which focuses on maternal and paternal mean corpuscular volume (MCV) alone. Normal paternal MCV may not preclude fetal Hb Bart's disease because of the rare occurrence of maternal uniparental disomy or non-paternity. During a mid-trimester anomaly scan, with fetal cardiomegaly or hydrops in a woman with low MCV but normal paternal MCV, obstetricians should remain alert for fetal Hb Bart's disease. This is very important and relevant for national screening systems in South-East Asia, where a routine mid-trimester scan may not be available. A routine mid-trimester anomaly scan should therefore be implemented and in high prevalence areas, sonographers should be sensitive to the cardio-thoracic ratio even if screening shows that pregnancy is unlikely to be at risk.

Knowledge of cardiopulmonary resuscitation among the public in Hong Kong: telephone questionnaire survey

OBJECTIVES

To evaluate the knowledge of basic life-support and training experience in cardiopulmonary resuscitation among the public in Hong Kong and to identify areas for improvement in public education.

DESIGN

Telephone interview using a structured multiple-choice questionnaire.

SETTING

Random cross-section of the Hong Kong public, from mid-March to May 2002.

PARTICIPANTS

Men and women aged 16 years and older selected using random telephone dialling.

MAIN OUTCOME MEASURE

Overall score in the cardiopulmonary resuscitation knowledge questionnaire.

RESULTS

Of the 357 participants, approximately 12% had received cardiopulmonary resuscitation training. Cardiopulmonary resuscitation knowledge in Hong Kong was poor, even among the previously trained and especially with regard to circulatory maintenance. The most common reason for not taking cardiopulmonary resuscitation training was lack of time.

CONCLUSION

The degree of citizen preparedness in initiating cardiopulmonary resuscitation is very poor in Hong Kong. Intensified educational efforts and exploration of new approaches to improve this first stage in the chain of survival are warranted.