ABSTRACT
<p><b>INTRODUCTION</b>We 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.</p><p><b>METHODS</b>Selected informative STRs located on translocated arms of relevant chromosomes were used to discriminate between normal and unbalanced chromosome states in each embryo.</p><p><b>RESULTS</b>PGD 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.</p><p><b>CONCLUSION</b>STR analysis is a simple and suitable alternative to FISH for detecting unbalanced chromosomal states in preimplantation embryos.</p>
Subject(s)
Female , Humans , Male , Pregnancy , Fertilization in Vitro , Microsatellite Repeats , Genetics , Polymerase Chain Reaction , Methods , Polymorphism, Genetic , Genetics , Pregnancy Outcome , Preimplantation Diagnosis , Methods , Translocation, Genetic , GeneticsABSTRACT
<p><b>INTRODUCTION</b>We report on the first successful preimplantation genetic diagnosis (PGD) in Singapore.</p><p><b>CLINICAL PICTURE</b>A couple who are beta-thalassaemia carriers and have an affected daughter requested for PGD.</p><p><b>TREATMENT</b>Two 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.</p><p><b>OUTCOME</b>A singleton pregnancy was achieved in the second PGD cycle, resulting in the birth of a healthy baby boy with carrier genotype.</p><p><b>CONCLUSIONS</b>This case report documents the first successful PGD in Singapore, involving a couple at-risk of transmitting beta-thalassaemia major.</p>
Subject(s)
Adult , Female , Humans , Male , Pregnancy , Fertilization in Vitro , Preimplantation Diagnosis , Risk Factors , Singapore , beta-Thalassemia , Diagnosis , GeneticsABSTRACT
<p><b>INTRODUCTION</b>We 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.</p><p><b>CLINICAL PICTURE</b>Two 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.</p><p><b>TREATMENT</b>One 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.</p><p><b>OUTCOME</b>Couple 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.</p><p><b>CONCLUSIONS</b>We have successfully performed PGD to avoid Hb Bart's hydrops fetalis syndrome.</p>
Subject(s)
Adult , Female , Humans , Male , Pregnancy , Embryo Transfer , Genetic Carrier Screening , Genetic Testing , Hemoglobins, Abnormal , Hydrops Fetalis , Diagnosis , Genetics , Minisatellite Repeats , Genetics , Ovulation Induction , Methods , Polymerase Chain Reaction , Pregnancy Complications, Hematologic , Diagnosis , Genetics , Preimplantation Diagnosis , Singapore , Sperm Injections, Intracytoplasmic , alpha-Globins , GeneticsABSTRACT
<p><b>INTRODUCTION</b>Williams 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.</p><p><b>CLINICAL PICTURE</b>We report a child with these genetic aberrations, highlighting the clinical characteristics of such an individual.</p><p><b>CONCLUSION</b>The manifestations and interactions of both conditions are also discussed.</p>