INTRODUCTIONWe report the fi rst successful preimplantation genetic diagnosis (PGD) for Hb Bart's hydrops fetalis in Singapore, involving both fresh and frozen embryo replacement cycles.

CLINICAL PICTURETwo couples who were carriers of the Southeast Asian type double gene deletion (--(SEA) deletion carriers) requested for PGD. Couple A had 2 previous affected pregnancies, while couple B have a child of unknown genotypic status.

TREATMENTOne PGD cycle was performed for each couple. The --(SEA) deletion was detected using a gap-PCR strategy. Couple A had 1 fresh-embryo replacement cycle while couple B underwent 2 frozen-embryo replacement cycles.

OUTCOMECouple A achieved a twin pregnancy. Second trimester complications resulted in premature delivery, where 1 baby girl survived. Couple B achieved a singleton pregnancy resulting in delivery of a healthy baby boy. Genotype analysis of all babies confirmed the PGD results consistent with clinically unaffected status.

CONCLUSIONSWe have successfully performed PGD to avoid Hb Bart's hydrops fetalis syndrome.

Adult ; Embryo Transfer ; Female ; Genetic Carrier Screening ; Genetic Testing ; Hemoglobins, Abnormal ; Humans ; Hydrops Fetalis ; diagnosis ; genetics ; prevention & control ; Male ; Minisatellite Repeats ; genetics ; Ovulation Induction ; methods ; Polymerase Chain Reaction ; Pregnancy ; Pregnancy Complications, Hematologic ; diagnosis ; genetics ; prevention & control ; Preimplantation Diagnosis ; Singapore ; Sperm Injections, Intracytoplasmic ; alpha-Globins ; genetics

INTRODUCTIONWilliams syndrome (WS) is a rare but well recognised neurodevelopmental disease affecting the connective tissue and the central nervous system. Many patients are identified through the presence of dysmorphic features and associated cardiac abnormalities. Klinefelter syndrome (KS) is associated with gynaecomastia, small testes, azoospermia and elevated gonadotropin levels. They are recognised in the second decade of life by their tall stature and delay in pubertal development. A combination of constitutive WS and KS has yet to be described.

CLINICAL PICTUREWe report a child with these genetic aberrations, highlighting the clinical characteristics of such an individual.

CONCLUSIONThe manifestations and interactions of both conditions are also discussed.

Body Height ; Body Weight ; Child, Preschool ; Comorbidity ; Humans ; In Situ Hybridization, Fluorescence ; Klinefelter Syndrome ; diagnosis ; epidemiology ; Male ; Williams Syndrome ; diagnosis ; epidemiology

INTRODUCTIONWe report on the first successful preimplantation genetic diagnosis (PGD) in Singapore.

CLINICAL PICTUREA couple who are beta-thalassaemia carriers and have an affected daughter requested for PGD.

TREATMENTTwo cycles of PGD were performed on the couple. Beta-thalassaemia mutations were detected using a nested PCR and minisequencing strategy, and unaffected embryos were selected for transfer.

OUTCOMEA singleton pregnancy was achieved in the second PGD cycle, resulting in the birth of a healthy baby boy with carrier genotype.

CONCLUSIONSThis case report documents the first successful PGD in Singapore, involving a couple at-risk of transmitting beta-thalassaemia major.

Adult ; Female ; Fertilization in Vitro ; Humans ; Male ; Pregnancy ; Preimplantation Diagnosis ; Risk Factors ; Singapore ; beta-Thalassemia ; diagnosis ; genetics ; prevention & control

INTRODUCTIONWe aimed to develop and implement a short tandem repeat (STR) polymerase chain reaction alternative to fluorescence in situ hybridisation (FISH) for the preimplantation genetic diagnosis (PGD) of chromosomal translocations.

METHODSSelected informative STRs located on translocated arms of relevant chromosomes were used to discriminate between normal and unbalanced chromosome states in each embryo.

RESULTSPGD cycles were performed on five couples where one spouse carried a balanced translocation. 27 embryos were analysed, of which 12 were normal/balanced, 12 were abnormal/unbalanced and three were indeterminate. Four PGD cycles proceeded to embryo transfer, of which two led to pregnancy. The first pregnancy showed a normal male karyotype, and a healthy baby was delivered at term. A second pregnancy unexpectedly miscarried in the second trimester from unknown causes.

CONCLUSIONSTR analysis is a simple and suitable alternative to FISH for detecting unbalanced chromosomal states in preimplantation embryos.

Female ; Fertilization in Vitro ; Humans ; Male ; Microsatellite Repeats ; genetics ; Polymerase Chain Reaction ; methods ; Polymorphism, Genetic ; genetics ; Pregnancy ; Pregnancy Outcome ; Preimplantation Diagnosis ; methods ; Translocation, Genetic ; genetics

Objectives. Polymorphisms in metabolic genes which alter rates of bioactivation and detoxification have been shown to modulate susceptibility to colorectal cancer. This study sought to evaluate the colorectal cancer risk from environmental factors and to do polymorphism studies on genes that code for Phase I and II xenobiotic metabolic enzymes among Filipino colorectal cancer patients and matched controls. Methods. A total of 224 colorectal cancer cases and 276 controls from the Filipino population were genotyped for selected polymorphisms in GSTM1, GSTP1, GSTT1, NAT1 and NAT2. Medical and diet histories, occupational exposure and demographic data were also collected for all subject participants.Results. Univariate logistic regression of non-genetic factors identified exposure to UV (sunlight) (OR 1.99, 95% CI: 1.16-3.39) and wood dust (OR 2.66, 95% CI: 1.21-5.83) and moldy food exposure (OR 1.61, 95% CI:1.11-2.35) as risk factors; while the NAT2*6B allele (recessive model OR 1.51, 95% CI :1.06-2.16; dominant model OR 1.87, 95% CI: 1.05-3.33) and homozygous genotype (OR 2.19, 95% CI: 1.19-4.03) were found to be significant among the genetic factors. After multivariate logistic regression of both environmental and genetic factors, only UV radiation exposure (OR 2.08, 95% CI: 1.21-3.58) and wood dust exposure (OR 2.08, 95% CI: 0.95-5.30) remained to be significantly associated with increasing colorectal cancer risk in the study population.Conclusion. This study demonstrated that UV sunlight and wood dust exposure play a greater role in influencing colorectal cancer susceptibility than genotype status from genetic polymorphisms of the GST and the NAT` genes.
Colorectal Neoplasms ; Polymorphism, Genetic