OBJECTIVE: To explore the clinical characteristics and gene variant of a fetus with Farber lipogranulomatosis caused by ASAH1 gene variant. METHODS: A fetus with Farber lipogranulomatosis caused by ASAH1 gene variant diagnosed at Women and Children's Hospital of Ningbo University in August 2024 was selected as the subject. Clinical data and abortion tissue samples of the fetus and peripheral blood samples of its parents were collected for whole exome sequencing (WES). Sanger sequencing validation and bioinformatics analysis were performed on candidate variants. This study was approved by Women and Children's Hospital of Ningbo University (Ethics No. EC2020-048). RESULTS: Generalized skin oedema, pericardial effusion, right pleural effusion and increased bowel echogenicity of the fetus were founded by prenatal ultrasound. WES revealed that the fetus has harbored a homozygous c.101C>A (p.Ser34Ter) variation in exon 2 of the ASAH1 gene. Sanger sequencing confirmed that both parents carry the heterozygous nonsense variation c.101C>A (p.Ser34Ter) in ASAH1 gene, which has not been included in databases such as HGMD, ClinVar, 1000 Genomes, ExAC, dbSNP, and gnomAD. Based on the Standards and Guidelines for the Interpretation of Sequence Variants of the American College of Medical Genetics and Genomics (ACMG), the variant was predicted to be pathogenic (PM2_Supporting+PVS1+PM3_Supporting). The AlphaFold3 model protein structure prediction reveals that the c.101C>A variant caused the premature appearance of a termination codon, resulting in only a small partial α-helix structure in the N-terminal of the encoded ASAH1 protein, with the complete loss of the α-helix structure in the core domain, which might lead to the loss of function of this protein. CONCLUSION The c.101C>A (p.Ser34Ter) variant of the ASAH1 gene probably underlay the Farber lipogranulomatosis with hydrops fetalis in this fetus. The newly discovered c.101C>A (p.Ser34Ter) variant has enriched the mutational spectrum of Farber lipogranulomatosis.
Humans ; Female ; Pregnancy ; Acid Ceramidase/chemistry* ; Farber Lipogranulomatosis/diagnostic imaging* ; Fetus ; Exome Sequencing ; Adult

OBJECTIVE: One of the models we study is the ovarian granulosa cell (GC), a somatic cell lineage that is critically important for maintenance of the female germ line and many endocrine functions of the ovaries. The objective of this study is to clarify the significance of ceramide and the role of ceramide metabolism in dictating the fate of cells exposed to stress. METHODS: We first treated GC with a C8-ceramide analog or an amine derivative of ceramide that cannot be metabolized by ceramidase (C8-ceramine). Northern blot analysis was performed to evaluate mRNA of acid ceramidease expression regualted by gonadotropin and in situ hybridization was done to identify the mRNA expression of acid ceramidase in ovaries. RESULTS: After 6 hours, C8-ceramide (50 micro M) triggered apoptosis in only 28 +/- 6% of the cells, whereas C8-ceramine (50 micro M) induced apoptosis in all cells (LD50=1 micro M). These data suggested that ceramidase activity is a critical determinant of GC survival. In situ hybridization showed that mRNA of acid ceramidase was highly expressed in GC in growing follicle. mRNA of acid ceramidase was expressed abundantly in granulosa cells and ovaries and its expression was significantly increased by gonadotropin in granulosa cells in in situ hybridization. Forty two hour after gonadotropin treatment, mRNA expression of acid ceramidase in granulosa cells was two fold increased cells comparing with no treatment control in northern blot analysis (P<0.05). In copora lutea, elevated mRNA expression of acid ceramidase was decreased. CONCLUSION: We concluded that GC possess inherently high levels of ceramidase activity, and that ceramidase has important for metabolizing ceramind to maintain GC survival in the ovary.
Acid Ceramidase ; Apoptosis ; Blotting, Northern ; Cell Lineage ; Ceramidases* ; Female ; Germ Cells ; Gonadotropins ; Granulosa Cells* ; Humans ; In Situ Hybridization ; Metabolism ; Ovary ; RNA, Messenger