Objective To explore the value of systematic continuous sequence approach combined with two- and three-dimensional ultrasonography in screening of fetal hand deformity. Methods Systematic continuous sequence approach was performed with two- and three-dimensional u1trasonography in 28 541 cases to detect the fetal hand from January 2011 to December 2014 in the 105th Hospital of PLA. Prenatal ultrasonic diagnosis was compared with clinical delivery follow-up and pathology results of induced labour, then prenatal ultrasound features of various fetal hand deformities and the causes of missed diagnosis were analyzed. Results Thirty-four cases of fetal hand deformity were diagnosed out of 28 541 fetuses by prenatal ultrasonography (43 hands). In the 34 cases, there were 5 cases of cleft hand, 13 cases of ectrodactyly with fingers abnormal morphology, 3 cases of forearm and hand dysplasia, 7 cases of wrist or finger abnormal posture and 6 cases of hand absence of abnormal. Three missed cases included 1 case of polydacty, 1 case of middle phalanx and distal phalanx of the little thumb absence and 1 case of middle phalanx of little thumb absence. Hand deformity rate was 0.13%(37/28 541). The detection rate ofprenatal ultrasonography was 91.89%(34/37). The rate of hand deformity complicated deformity with one or more other organ was 52.94%(18/34). The rate of chromosome abnormalities was 13.51%(5/37). Cleft hand showed that fetal hand from the central longitudinal split into two halves. Ectrodactyly with fingers abnormal morphology showed that one or multiple fingers were absent combined with residual finger abnormal morphology. Forearm and hand dysplasia showed that the forearm was abnormally developed, the ulna and radius were short and the structure of the wrist disappeared. Wrist or finger abnormal posture showed that a hook-shaped wrist or half fist shaped hand, thumb adduction flexion, the index finger bending baroclinic on the dorsal of the middle finger and small finger bending baroclinic on the dorsal of the ring finger dorsal. Hand absence showed that no fetal hands. Conclusions Application of systematic continuous sequence approach combined with real time three-dimensional ultrasonography in the diagnosis of fetal hand deformity, such as ectrodactyly with fingers abnormal morphology and wrist or finger abnormal posture, can make up for the shortage of two-dimensional ultrasonography and obtain more diagnostic information.

Objective:To investigate the clinical and biological characteristics of relapsed childhood low-risk acute B lymphoblastic leukemia (B-ALL).Methods:The clinical and laboratory data of 34 children who admitted in Beijing Boren Hospital from July 2017 to July 2018 were retrospectively analyzed, and 127-339 mutations of hematological malignancy related genes were analyzed.Results:The median time from the diagnosis to the recurrence was 871 d (87-1 446 d). The recurrence at early stage and late stage had 26 cases (76%) and 8 cases (24%), respectively. The recurrence before maintenance treatment, during maintenance therapy and after withdrawal of chemotherapy had 3 cases (9%), 12 cases (35%) and 19 cases (56%) (13 cases relapsed within 1 year after withdrawal, 6 cases relapsed after withdrawal 1-2 years and no one relapsed after withdrawal 2 years). The sites of recurrence included bone marrow alone accounting for 26 cases (76%), both intramedullary and extramedullary disease (EMD) accounting for 6 cases (18%), EMD alone accounting for 2 cases (6%). Flow cytometry showed that 9 patients presented minimal residual disease (MRD)-positive (6 cases with one positive, 2 cases with twice positive and 1 case with 3 times positive), including 8 cases occurred at early stage and 1 case occurred at late stage; and the level of MRD was 0.02%-3.82%. Complex chromosomal karyotype appeared in 6 relapsed children with normal or hyperdiploid karyotype at first diagnosis. Hematological malignancy related gene mutation detection was made in 28 cases, and the results showed that each patient had at least one gene mutation, and 2 or more gene mutations were detected in 25 cases (89%). The high frequency of gene mutations were as follows: CREBBP (7 cases, 25%), NRAS (7 cases, 25%), KRAS(7 cases, 25%), TP53 (4 cases, 14%), and NT5C2 (4 cases, 14%).Conclusions:The recurrence of childhood low-risk B-ALL occurs mostly in the maintenance treatment or in two years of withdrawal of chemotherapy. Positive MRD after complete remission is likely to show the risk of early recurrence. The gene mutations after the poor prognosis in cancer cells may be related to the recurrence of childhood low-risk B-ALL, and the common gene mutations include CREBBP, RAS signaling pathways genes and TP53, NT5C2.