Incidental discovery of DMD gene deletions by chromosomal microarray analysis / 中华医学遗传学杂志

OBJECTIVE@#To discuss the value of chromosomal microarray analysis (CMA) for the identification of DMD gene deletions during prenatal diagnosis.@*METHODS@#G-banded karyotyping and CMA were performed on fetuses with ultrasonographic soft markers but no family history for Duchenne/Becker muscular dystrophy (DMD/BMD). Denaturing high-performance liquid chromatograghy (DHPLC) was used to detect DMD gene mutations in umbilical cord blood and peripheral blood samples from the mothers.@*RESULTS@#For fetus 1, analysis of amniocytes showed a normal karyotype, while CMA detected a 119 kb deletion at Xp21.1 (32 565 489 - 32 681 461), which encompassed exons 10 to 16 of the DMD gene. The result was confirmed by DHPLC analysis. The mother was found to have loss of heterozygosity in the same region. For fetus 2, karyotyping of amniocytes also showed a normal male karyotype, while CMA detected a 254 kb deletion at Xp21.1 (32 104 604 - 32 358 874), which encompassed exons 41 to 44 of the DMD gene. The same deletion was not detected in the mother. DHPLC analysis confirmed the presence of both deletions.@*CONCLUSION@#Two fetuses harboring DMD gene deletions but without a family history were discovered. CMA can improve the efficiency for detecting single gene diseases caused by deletions.

Prenatal diagnosis of fetal ring chromosome 18 with deletion: a case report / 中华围产医学杂志

We hereby reported a case of ring chromosome 18 complicated by the deletion of 18p11.32p11.31 and 18q21.33q23 diagnosed prenatally by G-banding karyotype and chromosomal microarray analysis (CMA). Ultrasound scan indicated a single umbilical artery and intrauterine growth retardation at the second trimester. The result of G-banding karyotyping was 46, XN, r(18)(p11.3q21.3) and CMA indicated that there was a 3.3 Mb deletion at 18p11.32p11.31 and a 16.9 Mb deletion at 18q21.33q23. All these suggested that the fetus might present with clinical manifestations such as growth retardation, epilepsy, speech delay and growth hormone deficiency after birth, so the couple decided to terminate the pregnancy after genetic counseling.

Effects of intramuscular and oral mecobalamin in elderly patients with vitamin B12 deficiency / 中国综合临床

Objective To investigate the effect of intramuscular and oral mecobalamin on hematologic markers and neurologic signs in elderly patients with vitamin B12 deficiency.Methods One hundred and twenty-six patients with vitamin B12 deficiency who fulfilled the inclusion criteria were randomly divided into 3 groups,42 cases in each,including the intramuscular group (to receive mecobalamin therapy intramuscularly),the oral group ( to receive mecobalamin therapy orally) and the control group ( without mecobalamin therapy).The changes of hematologic markers including hemoglobin (Hb,g/L),mean corpuscular volume (MCV,fl),serum levels of vitamin B12 (ng/L),folate and total homocysteine (Hcy,μmol/L),and neurological signs before and after treatment were compared among these groups.Results Baseline characteristics among the three groups were similar.After a 6-month therapy,there were no differences in any markers in control group patients in comparison to baseline;for patients in the intramuscular group,the blood vitamin B12 levels increased from (139.13 ± 31.57)ng/L to (328.10 ± 42.35 )ng/L (P ＜ 0.001 ).Hcy levels decreased from (36.29 ± 16.23 )μmol/L to ( 18.23 ± 9.85 ) μmol/L ( P ＜ 0.001 ).Hb rose from ( 125.34 ± 16.21 ) g/L to ( 132.79 ± 15.98 )g/L (P =0.037).MCV reduced from (92.98 ±5.35)fl to (87.65 ±5.74)fl (P ＜0.001 ) ;For patients in the oral administration group,the blood vitamin B12 levels increased from ( 138.19 ± 29.95) ng/L to (487.79 ±32.21 ) ng/L ( P ＜ 0.001 ).Hcy levels decreased from ( 33.27 ± 11.51 ) μmol/L to ( 17.49 ± 10.13 ) μmol/L( P ＜ 0.001 ).Hb rose from ( 125.89 ± 17.65 ) g/L to ( 133.46 ± 16.26) g/L ( P =0.041 ).MCV reduced from (93.08 ± 5.10 ) fl to ( 89.29 ± 5.37 ) fl ( P =0.001 ).After the 6-month therapy,there were somewhat improvement in MMSE scores of the intramuscular ( 28.24 ± 3.89 vs.27.85 ± 3.56,P =0.633 ) and the oral groups (27.97 ± 3.77 vs.27.34 ± 3.15,P =0.408 ) compared with baseline,but the differences were not significant.The achilles tendon reflex of the intramuscular ( 1.86 ± 0.67 vs.1.56 ± 0.61,P =0.035 ) and the oral groups ( 1.79 ± 0.64 vs.1.43 ± 0.51,P =0.006 ) were enhanced compared with baseline.Foot vibration sensation of the intramuscular ( 1.35 ± 0.37 vs.1.06 ± 0.41,P =0.001 ) and the oral groups ( 1.24 ± 0.52vs.1.01 ± 0.43,P =0.03) were improved compared with baseline.After treatment,the serum VitB12 concentration in the oral group were higher than that of the intramuscular group ( P ＜ 0.001 ).There were no significant differences in other indexes between the two groups.Conclusion Mecobalamin,administered either intramuscularly or orally,may improve the hematologic markers and neurologic signs in elderly patients with vitamin B12 deficiency.