Prenatal diagnosis of 5 fetuses with high risk of developing spinal muscular atrophy / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To perform prenatal diagnosis for 5 pregnant women who had given birth to children with spinal muscular atrophy (SMA).</p><p><b>METHODS</b>Thirty to forty mililiters of amniotic fluid was obtained by amniocentesis under ultrasonic monitoring. DNA was extracted directly from sediment of amniotic fluid. Short tandem repeat (STR) profiling was carried out to evaluate the contamination of amniotic DNA by maternal genomic DNA. Two methods, PCR-restriction fragment length polymorphism (PCR-RFLP) and allele-specific PCR, were used to analyze exon 7 of SMN gene from amniotic DNA.</p><p><b>RESULTS</b>Comparing the 16 STR sites of each fetus with those of his/her parents, there was no or little contamination of amniotic DNA by maternal genomic DNA. In conventional PCR-RFLP, part of the PCR product (189 bp) from amniotic DNA of fetus A, C, or D remained intact after digestion with Dra I, while the PCR product from amniotic DNA of fetus B or E was completely digested by Dra I. In allele-specific PCR, exon 7 of both SMN1 and SMN2 gene could be seen when amniotic DNA of fetuses A, C, or D was analyzed, while only exon 7 of SMN2 could be seen when amniotic DNA of fetuses B or E was analyzed.</p><p><b>CONCLUSION</b>Homozygous deletion of SMN1 is not detected in fetuses A, C, and D, predicting that the risk of developing SMA after birth would be extremely low. Homozygous deletion of SMN1 was present in fetuses B and E suggesting high risk of developing SMA after birth.</p>

Prenatal molecular diagnosis of adrenoleukodystrophy / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To carry out prenatal diagnosis on two fetuses of different pedigrees with X-linked adrenoleukodystrophy (ALD).</p><p><b>METHODS</b>The amniotic fluid was obtained with the help of a clinical doctor and the genomic DNA was isolated from it. Maternal DNA contamination was excluded by fluorescent STR profiling, The R617G mutation found in the first pedigree was searched in genomic DNA of amniotic fluid cells (AFC) from fetus 1 by amplification refractory mutation system (ARMS) and dot DNA hybridization while the P534R mutation found in pedigree 2 was analyzed in the AFC genomic DNA of fetus 2 by restrictive digestion with Hae II and DNA direct sequencing.</p><p><b>RESULTS</b>A specific band (185 bp) was detected from the genomic DNA of the first fetus and his mother by using mutation primer in ARMS but not from that of the first fetus's father and unrelated controls. DNA dots were visualized only in the fetus 1 and carrier when using the mutation probe in DNA hybridization. In the other ALD family, the PCR product (506 bp) of the second fetus which spanned the site of P534R mutation could not be digested with Hae II and no mutation was detected in the ABCD1 gene from the genomic DNA of the fetus 2 by using DNA direct sequencing.</p><p><b>CONCLUSION</b>Fetus 1 had R617G mutation on his ABCD1 gene and he was an adrenoleukodystrophy hemizygote. Fetus 2 had no P534R mutation on his ABCD1 gene and he was a normal hemizygote.</p>

Mutational analysis of three Chinese pedigrees with adrenoleukodystrophy / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To identify the mutational genotype of three Chinese families with X-linked adrenoleukodystrophy (X-ALD: MIM#300100).</p><p><b>METHODS</b>Total RNA was extracted from the peripheral blood leukocytes of patients 1, 2 and the mother of patient 3, using RNA blood Mini kit (QIAGEN). After reverse transcription, cDNA was amplified in four overlapping segments. The PCR products were purified and directly sequenced. To confirm the mutations, the genomic DNA was isolated from the patients and their family members using DNA blood isolation kit (MO-BIO) and analyzed by PCR-restrictive digestion or amplification refractory mutation system.</p><p><b>RESULTS</b>Three distinct mutations were detected in the ABCD1 gene of the three pedigrees. A mutation of CCC-->CGC was detected at codon 534 of the ABCD1 gene from patient 1, resulting in the arginine for proline substitution. A change of GGG-->AGG was found at codon 266 of the second patient's gene, accompanied with the replacement of glycine by arginine. A mutation of CGC-->GGC was found at codon 617 in one ABCD1 allele of the third patient's mother, leading to the glycine for arginine substitution. The three mutations were confirmed through restriction analysis or amplification refractory mutation system.</p><p><b>CONCLUSION</b>Three ABCD1 gene missense mutations were detected in three unrelated Chinese families with X-linked adrenoleukodystrophy, one of which, the mutation (P534R), is novel in Chinese with ALD, and the other two G266R and R617G mutations, have been reported outside China.</p>

Changes of cerebral vascular hemodynamics from normal population to stroke / 中华流行病学杂志

<p><b>OBJECTIVE</b>To probe into changes of cerebral vascular hemodynamics indexes (CVHI) from normal population to different clinical stage before and after occurring of stroke.</p><p><b>METHODS</b>Participants were selected from 25,355 stroke cohort study population aged 35 years and over in Northeast of China and 55 acute stroke patients were selected from Fuzhou PLA General Hospital. CVHI indexes were checked during baseline investigation or within one week after acute stroke. Participant enlisted in the study were divided into following 5 groups, normal population, high risk population, individuals before stroke, acute stroke patients and convalescence stroke patients. Characteristics of CVHI indexes in different population were analyzed and compared.</p><p><b>RESULTS</b>V(min) of cerebral vascular in previous defined 5 group participants were 11.39 +/- 3.27, 9.66 +/- 3.18, 6.71 +/- 3.30, 4.13 +/- 1.27, 6.78 +/- 3.09, respectively. V(mean) and V(max) were with the same decreasing trends as V(min). However, RV in 5 group participants were 62.35 +/- 21.11, 82.32 +/- 31.16, 122.72 +/- 52.73, 137.46 +/- 49.56 and 115.89 +/- 55.51, respectively. Zcv, WV, DR and CP were also with the same increasing trends as RV. Abnormal rate of CVHI score (< 75 points) from normal population to convalescence stroke patients were 13.3%, 34.7%, 74.1%, 100% and 66.7%, respectively.</p><p><b>CONCLUSION</b>From normal population to clinical stage of stroke, cerebral vascular velocity showed decreasing trends while other indexes, such as RV, Zcv, WV, DR and CP were increasing.</p>