Fam78b, also known as Family with sequence similarity 78, member B, has been implicated in a variety of biological functions and disease associations. Although its exact molecular function remains to be fully elucidated, studies suggest it may be involved in pathways related to metabolism, cardiovascular health, and potentially reproduction [3,4]. Genetic models could potentially help in further understanding its role at a mechanistic level.

A 38-year-old male patient with thiamine-responsive megaloblastic anemia syndrome had a 3.4 Mb inversion in the chromosomal region 1q24.2 with breaking points in FAM78B and SLC19A2, indicating a possible role of FAM78B in this rare autosomal recessive disease [1]. In a longitudinal genetic epidemiological study in Japan, the SNP rs2116519 of FAM78B was significantly associated with the prevalence of hypertension, diastolic blood pressure, and blood glycosylated hemoglobin content in type 2 diabetes mellitus patients [2,7]. Genome-wide association studies also suggest that FAM78B may be a susceptibility locus for chronic kidney disease in Japanese individuals [6]. Additionally, a genome-wide association study of phenotypes measuring progression from first cocaine use to dependence identified a variant in FAM78B associated with time to dependence [5].

In conclusion, FAM78B appears to be associated with multiple disease conditions, including thiamine-responsive megaloblastic anemia syndrome, hypertension, type 2 diabetes mellitus, chronic kidney disease, and cocaine dependence. The findings from these studies highlight the potential importance of FAM78B in understanding the genetic basis of these diseases, although more research, potentially using gene knockout or conditional knockout mouse models, is needed to clarify its exact functions and mechanisms in these disease contexts.

References:

1. Klötzer, Christina, Schnabel, Franziska, Kubasch, Anne-Sophie, Vučinić, Vladan, Platzbecker, Uwe. 2024. Thiamine-Responsive Megaloblastic Anemia Syndrome Mimicking Myelodysplastic Neoplasm. In Acta haematologica, , 1-5. doi:10.1159/000542286. https://pubmed.ncbi.nlm.nih.gov/39467528/

2. Yamada, Yoshiji, Matsui, Kota, Takeuchi, Ichiro, Oguri, Mitsutoshi, Fujimaki, Tetsuo. 2015. Association of genetic variants with hypertension in a longitudinal population-based genetic epidemiological study. In International journal of molecular medicine, 35, 1189-98. doi:10.3892/ijmm.2015.2151. https://pubmed.ncbi.nlm.nih.gov/25813534/

3. Rodrigues, Julia Lisboa, Braga, Larissa Graciano, Watanabe, Rafael Nakamura, Buzanskas, Marcos Eli, Munari, Danísio Prado. 2025. Genetic diversity and selection signatures in sheep breeds. In Journal of applied genetics, , . doi:10.1007/s13353-025-00941-z. https://pubmed.ncbi.nlm.nih.gov/39883377/

4. Saini, Tapendra, Chauhan, Anuj, Ahmad, Sheikh Firdous, Gaur, G K, Dutt, Triveni. 2024. Elucidation of population stratifying markers and selective sweeps in crossbred Landlly pig population using genome-wide SNP data. In Mammalian genome : official journal of the International Mammalian Genome Society, 35, 170-185. doi:10.1007/s00335-024-10029-4. https://pubmed.ncbi.nlm.nih.gov/38485788/

5. Sherva, Richard, Zhu, Congcong, Wetherill, Leah, Gelernter, Joel, Farrer, Lindsay A. 2021. Genome-wide association study of phenotypes measuring progression from first cocaine or opioid use to dependence reveals novel risk genes. In Exploration of medicine, 2, 60-73. doi:10.37349/emed.2021.00032. https://pubmed.ncbi.nlm.nih.gov/34124712/

6. Yamada, Yoshiji, Nishida, Tamotsu, Ichihara, Sahoko, Fukuda, Michio, Sawabe, Motoji. 2013. Identification of chromosome 3q28 and ALPK1 as susceptibility loci for chronic kidney disease in Japanese individuals by a genome-wide association study. In Journal of medical genetics, 50, 410-8. doi:10.1136/jmedgenet-2013-101518. https://pubmed.ncbi.nlm.nih.gov/23539754/

7. Yamada, Yoshiji, Matsui, Kota, Takeuchi, Ichiro, Oguri, Mitsutoshi, Fujimaki, Tetsuo. 2015. Association of genetic variants of the α-kinase 1 gene with type 2 diabetes mellitus in a longitudinal population-based genetic epidemiological study. In Biomedical reports, 3, 347-354. doi:. https://pubmed.ncbi.nlm.nih.gov/26137234/