which can be combined with oral feeding, most commonly a semi-elemental diet which allows patients to become independent of PN over time. Nutrition and growth should be closely monitored. If PN is not required, reports have described the use of an amino acid based formula, although it is unclear if weight gain was adequate. Immunoglobulin levels and vaccine responses should be tested. If any abnormalities are found then a paediatric immunologist should be consulted and intravenous immunoglobulin (IVIG) can be considered to reduce chance of systemic infections. Infection was reported as a cause of death in 20% of a large cohort of French patients. A recent study looked at immunodeficiency in 9 THES patients, of which 3 had SKIV2L pathogenic variants. The authors reported that the degranulation and number of IFN-γ producing NK cells were reduced in most patients (although it is unclear if this included the SKIV2L patients) and proposed that this could lead to susceptibility to RNA viruses, with 4/9 patients harbouring a chronic EBV infection and one patient dying of measles. Regular liver assessment should include ultrasound and hepatic enzymes and developmental assessment should be performed. Steroids, immunosuppressants and haematopoietic stem cell transplant has been THES with no success and therefore it is not recommended. Genetic counselling should be offered as a sibling recurrence is 25% with each conception. Age related macular degeneration (ARMD) An intronic single nucleotide polymorphism (SNP) in SKIV2L on genome wide association studies has been shown to be protective for age related macular degeneration. 3’UTR variant in SKIV2L has recently been reported to exert a protective effect in polypoidal choroidal vasculopathy, a haemorrhagic macular disease that shares some features with neovascular ARMD. As the variants would not affect structure of the protein, it was proposed that it affects regulation of oxidative stress pathways. Conversely another study showed a genetic variant rs429608 to be strongly associated with the development of ARMD in the Han Chinese population, however further studies are needed to investigate the biological role of SKIV2L and pathogenesis. Notes References Further reading