1.Clinical features of a pedigree of charcot-marie-tooth disease type 2cc caused by the point mutation of NEFH gene
Qianqian SHENG ; Peng ZHAO ; Shujuan CHEN ; Lin YUAN ; Weihang MU
Chinese Journal of Applied Clinical Pediatrics 2022;37(18):1420-1423
The clinical data of 4 patients in a pedigree of charcot-marie-tooth disease type 2cc (CMT2cc) caused by the NEFH gene mutation from the Department of Rehabilitation, Tianjin Children′s Hospital in March 2020 were reviewed and analyzed retrospectively.The purpose of this study was to improve clinicians′ awareness of the di-sease.The pedigree had signs and symptoms of varying degrees of pyramidal fasciculus involvement, high arched feet, and achilles tendon contracture.The electrophysiological testing of both lower extremities suggested sensory and motor nerve axonal damage, and an abnormal visual evoked potential was observed.Second-generation sequencing revealed that the pathogenic factor was the NEFH gene variation: c.1319G>A (p.Ser440Asn), which is a new mutation site that has never been reported before. NEFH mutations can cause a complex clinical phenotype of CMT2cc, which is therefore easily misdiagnosed.Central and peripheral nerves are simultaneously involved in CMT2cc patients.Electrophysiological testing and genetic analysis are required to clarify the diagnosis of CMT2cc.
2.Clinical and genetic analysis of a child with Alazami syndrome due to compound heterozygous variants of LARP7 gene.
Lin YUAN ; Peng ZHAO ; Qianqian SHENG ; Weihang MU ; Gang XU ; Jian LIU
Chinese Journal of Medical Genetics 2023;40(7):860-864
OBJECTIVE:
To analyze the clinical phenotype and genetic basis of a child with Alazami syndrome (AS).
METHODS:
A child who presented at Tianjin Children's Hospital on June 13, 2021 was selected as the study subject. The child was subjected to whole exome sequencing (WES), and candidate variants were verified by Sanger sequencing.
RESULTS:
WES revealed that the child has harbored two frameshifting variants of the LARP7 gene, namely c.429_430delAG (p.Arg143Serfs*17) and c.1056_1057delCT (p.Leu353Glufs*7), which were verified by Sanger sequencing to be respectively inherited from his father and mother.
CONCLUSION
The compound heterozygous variants of the LARP7 gene probably underlay the pathogenesis in this child.
Female
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Humans
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Dwarfism/genetics*
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Exome Sequencing
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Intellectual Disability/genetics*
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Microcephaly
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Mothers
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Mutation
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Male
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Child
3.NUDT2 gene induced intellectual disability with or without peripheral neuropathy: a case report and literature review
Weihang MU ; Peng ZHAO ; Qianqian SHENG ; Lin YUAN
Clinical Medicine of China 2024;40(2):104-108
Objective:To summarize the clinical characteristics and pathogenic mutation of gene NUDT2 in the child with intellectual disability with or without peripheral neuropathy (IDDPN). Methods:The clinical characteristics and development of one child attending the Department of Rehabilitation of Tianjin Children's Hospital were evaluated retrospectively,and the relationship between the clinical phenotype and gene mutation profile of NUDT2 was analyzed. Results:The child had global developmental delay, special appearance, low muscle tone of the limbs, accompanied by peripheral nerve damage in the limbs, and whole exome sequencing found that the child carried a homozygous mutation of NUDT2 gene, c.34C>T (p.R12X), which was a nonsense mutation. Sanger verified that both parents were carriers of c.34C>T heterozygous mutations. In the inclusion of 10 registered IDDPN patients, it was found that all of them were homozygous mutations, and the clinical phenotypes all had different degrees of cognitive impairment and movement disorders, among which only 3 cases were complicated by peripheral nerve damage. Conclusions:The child in this case had low birth weight/length, weak sucking ability in infancy, cognitive impairment, peripheral nerve damage, and genetic testing showed homozygous nonsense mutation of NUDT2 gene, which provided evidence support for the clinical understanding of the disease.