Prenatal Diagnosis of Sickle Cell Disease by the Technique of PCR

Abstract

Sickle cell disease (SCD) is prevalent in Central India and causes major morbidity and mortality. There is a lack of prenatal diagnostic facility near population affected with SCD. This is the pilot study in our region with the aim to establish prenatal diagnostic facility for the couples carrying sickle cell gene in Central India, in order to help them take an informed decision regarding fetus affected with SCD and also to calculate sensitivity of polymerase chain reaction (PCR) technique in our set up with follow up high performance liquid chromatography (HPLC) of baby's blood sample. Fetal sampling was done by chorionic villous biopsy. Extracted DNA was subjected to amplification refractory mutation system (ARMS-PCR) to detect sickle cell mutation (GAG ? GTG) in the sixth codon of b globin gene. Follow-up HPLC was done to detect baby's Hb pattern. Prenatal diagnosis of sickle cell anemia was offered in total 37 cases out of which one (2.7 %) fetal sample was inadequate. Total 26 (70.27 %) fetuses had AS Hb genotype, 3 (8.11 %) had AA Hb genotype and 3 (8.11 %) had SS Hb genotype while remaining 4 (10.81 %) were given AA/AS Hb genotype. All couples with SS fetuses opted for MTP. Follow up HPLC was performed in 24 cases, out of which 18 (75 %) were correlated and 6 (25 %) were mismatched. In present study sensitivity of ARMS-PCR was 75 %. ARMS-PCR is a simple technique to be established initially for providing rapid prenatal diagnosis to the couples with known sickle cell mutation. The sensitivity of ARMS-PCR can be increased by using suitable techniques to detect maternal cell DNA contamination.

Sickle cell disease

“…The Indian National Health Mission is making major contributions with their programmes in Gujarat, Maharashtra, Odisha and Chhattisgarh focused on population screening to determine disease prevalence, establishing newborn screening cohorts and standardizing hydroxyurea therapy 22 . Some programmes also deliver prenatal diagnosis, premarital screening and genetic counselling services 23 24 . The Ministry of Health and Family Welfare has released guidelines for a National Haemoglobinopathy Programme with emphasis on newborn screening and comprehensive care 1 .…”

Evaluation of amplification refractory mutation system (ARMS) technique for quick and accurate prenatal gene diagnosis of <em>CHM</em> variant in choroideremia

“… 33 Recently, Yang et al performed rapid gene diagnosis for retinitis pigmentosa, 34 and Singh et al performed prenatal gene diagnosis for sickle cell disease by ARMS. 35 More recently, Aquino et al performed ARMS-PCR to detect the most common mutations of the CFTR gene in Peruvian patients with cystic fibrosis. 36 Shah et al combined ARMS and DNA sequencing to diagnose β-thalassemia in East-Western Indian population for better management.…”

Evolving locally appropriate models of care for Indian sickle cell disease

“…These programmes have focused on population screening to get data on the prevalence and distribution of the sickle cell gene but extensive data are now available and there will be limited value in continuing to screen ever larger populations. Some programmes are being expanded to attempt prevention of the disease by prenatal diagnosis or by premarital screening and counselling carriers on the risk of having children affected by sickle cell disease 72 73 . These programmes are important but perhaps the time has come to use some of the resources destined for services to the sickle cell community to fund carefully planned studies of the natural history of sickle cell disease based on newborn screening.…”