Lack of CFAP54 causes primary ciliary dyskinesia in a mouse model and human patients / 医学前沿

Primary ciliary dyskinesia (PCD) is a highly heterogeneous recessive inherited disorder. FAP54, the homolog of CFAP54 in Chlamydomonas reinhardtii, was previously demonstrated as the C1d projection of the central microtubule apparatus of flagella. A Cfap54 knockout mouse model was then reported to have PCD-relevant phenotypes. Through whole-exome sequencing, compound heterozygous variants c.2649_2657delinC (p. E883Dfs*47) and c.7312_7313insCGCAGGCTGAATTCTTGG (p. T2438delinsTQAEFLA) in a new suspected PCD-relevant gene, CFAP54, were identified in an individual with PCD. Two missense variants, c.4112A>C (p. E1371A) and c.6559C>T (p. P2187S), in CFAP54 were detected in another unrelated patient. In this study, a minigene assay was conducted on the frameshift mutation showing a reduction in mRNA expression. In addition, a CFAP54 in-frame variant knock-in mouse model was established, which recapitulated the typical symptoms of PCD, including hydrocephalus, infertility, and mucus accumulation in nasal sinuses. Correspondingly, two missense variants were deleterious, with a dramatic reduction in mRNA abundance from bronchial tissue and sperm. The identification of PCD-causing variants of CFAP54 in two unrelated patients with PCD for the first time provides strong supportive evidence that CFAP54 is a new PCD-causing gene. This study further helps expand the disease-associated gene spectrum and improve genetic testing for PCD diagnosis in the future.

Advances in the Diagnosis, Treatment and Prognosis of Lymphangioleiomyomatosis / 罕见病研究

Lymphangioleiomyomatosis (LAM) is a rare, multisystemic, low-grade neoplasm character-ized by diffuse cystic lesions in the lung.In recent years, emerging imaging examination such as 68Ga-NEB PET-CT scan provides efficient and precise non-invasive diagnostic methods to detect lymphatic circulation abnormalities in LAM patients. The long-term efficacy and safety of sirolimus for LAM has accumulated further evidence, and genetic profiling studies have unveiled more information of genetic mechanisms. Prognosis of LAM has been much improved. We briefly reviewed the research advances of LAM in China and other countires.