In other species: domestic cat , rabbit

Categories: Haematopoietic system phene

Links to possible relevant human trait(s) and/or gene(s) in OMIM: 169400 (trait)

Mendelian trait/disorder: unknown

Disease-related: yes

Species-specific symbol: PHA

Species-specific description: Human Pelger-Huët anomaly is caused by heterozygous variants in the LBR gene and characterized by hyposegmentation of granulocytes. Bi-allelic loss of function of the LBR gene in humans results in Greenberg skeletal dysplasia, a severe condition involving prenatal lethality. All literature before 2023 hypothesized that dogs with hyposegmentation of granulocytes represent true homologs of the human Pelger-Huët anomaly, but the underlying causal genetic variant in dogs was unknown. Lourdes Frehner et al. (2023) demonstrated that a common form of hyposegmentation of granulocytes in dogs is actually caused by a variant in the LMBR1L gene (OMIA:002700-9615). Lourdes Frehner et al. (2023) proposed to reserve the term Pelger-Huët anomaly for LBR-related forms of hyposegmentation of granulocytes. At this time, it is not clear whether a true LBR-related form of PHA has ever been observed in dogs.

Clinical features: PHA is a leucocyte development-disorder, in which granulocytes and monocytes show hyposegmentation of the nuclei with a mature, coarse chromatin pattern (Latimer et al. 2000). Those changes are without any clinical relevance, but frequently lead to misdiagnosis as marked left shift, which is normally caused by inflammation, preleucaemic syndrome or drug induced changes in leucocyte morphology.