OBJECTIVE & DESIGN
Congenital Hypopituitarism (CH) is a complex developmental disorder characterized by variable pituitary dysfunction that is often associated with midline structural abnormalities that affect the brain, eyes and face. To date, only ∼10-15% of patients have an underlying molecular basis.
METHODS
Next generation sequencing was conducted on a subset of CH patients with no known genetic aetiology. Human embryonic brain tissue sections were used to generate an expression profile, and a knock-out mouse model was generated using CRISPR-Cas9 gene editing and phenotypically analysed.
RESULTS
Two novel homozygous frameshifts in CCDC149, p.Gly278* and p.Leu222*, were identified in two unrelated CH pedigrees (three patients), respectively. Patient phenotypes included growth hormone deficiency (GHD), hypogonadotropic hypogonadism, and developmental delay/autism. Severe scoliosis was present in one pedigree, with a small anterior pituitary on MRI in the other. Human embryonic CCDC149 was localised to the developing hypothalamo-pituitary region at Carnegie stages 16-23, and Ccdc149-null mice recapitulated patient phenotypes, including growth impairment and reduced fertility compared to wild-type littermates.
CONCLUSIONS
Our study is the first to report CCDC149 variants in association with CH. Previous studies in C.elegans report CCDC149 orthologue expression in the basal bodies of ciliated neurons, supporting the possibility of impaired ciliary function as an underlying mechanism in this complex disorder.
L. Gregory, Shoshana Rath, Hanna Mandel et al.· European Journal of Endocrin...· 0 citations
Recombinant adeno-associated virus (rAAV) vectors are widely used for in vivo gene therapy, yet their potential to integrate into the host genome raises concerns about insertional mutagenesis and oncogenic risk, particularly in the liver where vector exposure is highest. To address this, we analyzed rAAV integration patterns in primary human hepatocytes xenografted into FRG mouse livers and in hepatocytes from cynomolgus macaques following systemic rAAV administration. High-resolution integration site mapping yielded approximately 1.5 million and 1.3 million unambiguously mapped sites in human and macaque genomes, respectively. Both datasets revealed a bias toward integration within transcriptionally active genes and regions of open chromatin, consistent with previous reports, but no particular preference for genes implicated in hepatocellular carcinoma (HCC) was observed. While numerous common integration sites (CIS) were identified, their distribution differed between species. Notably, a CIS was observed at the AAVS1 locus in human hepatocytes, raising the possibility of Rep-mediated integration. These findings highlight the need for continued monitoring of integration events in clinical settings. Overall, the data support a low oncogenic risk profile for the evaluated vector while reinforcing the value of direct human liver integration analyses to refine risk assessment and guide the development of safer gene therapy platforms.
S. Scott, C. Hallwirth, Natsuki Sasaki et al.· Molecular Therapy· 0 citations