Antibody-drug conjugates (ADC) are one of the most popular types of anti-tumor drugs nowadays. Monomethyl auristatin E (MMAE), as a tubulin binder, is the most common applied payload in ADC and is also the main component that causes peripheral neuropathy (PN). By describing the clinical characteristics of 3 cases with MMAE ADC associated severe PN complications and analyzing reported references, this article summarizes that the occurrence of MMAE ADC associated PN is correlated with therapeutic cycles and duration of ADC, MMAE ADC associated PN is different from traditional chemotherapy-induced PN in the clinical presentation. Patients with MMAE ADC associated PN may present with a length-dependent involvement of peripheral motor and sensory nerves, and generally their weakness and deep sensory deficiency symptoms are more serious compared with traditional chemotherapy-induced PN. Two of the 3 patients achieved a relatively rapid recovery after treated with plasma exchange or immunoglobulin intravenous infusions.

Antibody-drug conjugates (ADC) are one of the most popular types of anti-tumor drugs nowadays. Monomethyl auristatin E (MMAE), as a tubulin binder, is the most common applied payload in ADC and is also the main component that causes peripheral neuropathy (PN). By describing the clinical characteristics of 3 cases with MMAE ADC associated severe PN complications and analyzing reported references, this article summarizes that the occurrence of MMAE ADC associated PN is correlated with therapeutic cycles and duration of ADC, MMAE ADC associated PN is different from traditional chemotherapy-induced PN in the clinical presentation. Patients with MMAE ADC associated PN may present with a length-dependent involvement of peripheral motor and sensory nerves, and generally their weakness and deep sensory deficiency symptoms are more serious compared with traditional chemotherapy-induced PN. Two of the 3 patients achieved a relatively rapid recovery after treated with plasma exchange or immunoglobulin intravenous infusions.

OBJECTIVETo achieve early diagnosis for inheritable hearing loss and determine carrier rate of deafness causing gene mutations in order to provide information for premarital, prenatal and postnatal genetic counseling.

METHODSA total of 17 000 dried heel blood spots of normal newborns in Chengdu were collected with informed consent obtained from their parents. Genomic DNA was extracted from dried blood spots using Qiagen DNA extraction kits. Microarrays with 9 common mutation loci of 4 deafness-associated genes in Chinese population were used. Nine hot mutations including GJB2 (35delG, 176del16, 235delC and 299delAT), GJB3 (538C> T), SLC26A4 (IVS 7-2A> G, 2168A> G), and mitochondrial DNA 12S rRNA (1555A> G, 1494C> T) were detected by PCR amplification and microarray hybridization. Mutations detected by microarray were verified by Sanger DNA sequencing.

RESULTSOf the 17 000 new-borns, 542 neonates had mutations of the 4 genes. Heterozygous mutations of GJB2, at 235delC, 299delAT, and 176del16 were identified in 254, 55, and 15 newborns, respectively. Two newborns had homozygous mutation of GJB2, 235delC. Heterozygous mutations at 538C> T of GJB3, 2168A> G and IVS 7-2A> G of SLC26A4 were found in 23, 17 and 128 newborns, respectively. For mutation analysis of mitochondrial DNA 12S rRNA, 1494C> T and 1555A> G were homogeneous mutations in 4 and 42 neonates, respectively. In addition, 6 complexity mutations were detected, which demonstrated that one newborn had heterozygous mutations at GJB2 235delC and SLC26A4, IVS7-2A> G, one had heterozygous mutation GJB2 235delC and 12S rRNA homogeneous mutation, 1555 A> G, one heterozygous mutations at GJB2, 299delAT, and GJB3, 538C> T, one at GJB2, 299delAT and 12S rRNA, 1555 A> G, two at GJB2, 299delAT, and SLC26A4, IVS7-2A> G. All mutations as above were confirmed by DNA sequencing.

CONCLUSIONThe total mutation carrier rate of the 4 deafness genes is 3.19% in healthy newborns at Chengdu. Mutations of GJB2 and SLAC26A4 are major ones (86.5% of total). The mutation rate of mitochondrial DNA 12S rRNA is 2.71‰, which may have deafness induced by aminoglycoside antibiotics. Newborn screening for mutation of genes related to hereditary deafness plays an important role in the early detection and proper management for neonatal deafness as well as genetic counseling for premarital, prenatal and postnatal diagnosis.

Asian Continental Ancestry Group ; genetics ; Base Sequence ; China ; Connexin 26 ; Connexins ; genetics ; DNA Mutational Analysis ; DNA, Mitochondrial ; chemistry ; genetics ; Deafness ; diagnosis ; ethnology ; genetics ; Dried Blood Spot Testing ; Genetic Predisposition to Disease ; ethnology ; genetics ; Genetic Testing ; methods ; Humans ; Infant, Newborn ; Membrane Transport Proteins ; genetics ; Microarray Analysis ; methods ; Mutation ; Neonatal Screening ; methods ; RNA, Ribosomal ; genetics