DOCK8 Deficiency: Transplanting Before the Complications Arrive
An eight-year-old with DOCK8 deficiency is doing reasonably well today. The argument is whether 'reasonably well' is the best transplant candidate she'll ever be, or a reason to wait until she's actually declining.
Priya M. is eight and lives with her parents and younger brother, who has never shown any of her symptoms despite sharing a bedroom with her for most of his life. Her DOCK8 deficiency was diagnosed at eighteen months after a pattern of severe eczema, multiple food allergies, and recurrent molluscum contagiosum and cutaneous herpes infections led to whole-exome sequencing showing biallelic pathogenic DOCK8 variants. She has had two episodes of pneumonia in her life, both treated successfully as an outpatient, and no history of the severe systemic viral infections, malignancy, or CNS vasculopathy that mark the disease's more advanced course in older patients. Her food allergies, confirmed by testing to include tree nuts and shellfish, are managed with strict avoidance and have not required an emergency epinephrine dose since a single episode at age four.
By her family's account and her team's own assessment, she is doing reasonably well today — attending school, playing on a recreational soccer team despite the molluscum lesions that occasionally flare on her arms, managed on immunoglobulin replacement and antiviral prophylaxis. Aydin et al., 2019, Journal of Allergy and Clinical Immunology in Practice, followed eighty-one DOCK8-deficient patients transplanted across twenty-two centers at a median age of 9.7 years, with 84% alive at median follow-up of twenty-six months — real, favorable numbers, and that paper is explicit that natural disease outcome without transplant is dismal. What it does not establish is the age argument her team is leaning on: its own comparison by age at transplant trended toward worse outcomes past about eight years but did not reach significance, and the sharper age-related survival decline comes from a separate natural-history cohort rather than from these eighty-one transplants. She is eight — a year and a half below that cohort’s median patient at transplant, and sitting exactly on the threshold where its own underpowered trend begins to bend the wrong way — which her team reads two different ways, and no CNS imaging or EBV surveillance to date has shown any early sign of the vasculopathy or lymphoproliferative complications the same literature associates with longer-standing, untreated disease.
The best candidate she'll ever be, or an unnecessary risk today
Aydin and colleagues followed eighty-one DOCK8 patients transplanted across twenty-two centers — 84% alive at follow-up, and the paper is explicit that untreated natural history is dismal. I’ll be straight that its own age comparison trended past eight years without reaching significance, and that the harder age-decline data is from the natural-history cohort, not this one. She turns eight this year. I want to start the referral and donor search today, while she's well, not wait for a complication to force the decision.
She is genuinely doing well — in school, playing soccer, no severe infections or malignancy. Transplant carries real conditioning risk, and I don't think 'her risk rises with age in general' is the same as 'she needs to be referred this year specifically.' I'd want to see this reasoning applied to her actual trajectory, not just the cohort average.
The 84% survival figure is reassuring, but it describes patients transplanted across a wide range of clinical states — it doesn't tell us whether transplanting her today, asymptomatic, buys her anything a well-monitored delay wouldn't.
I'd reframe the comparison. This isn't transplant-now versus never-transplant — everyone on this call agrees she'll eventually need it. The real choice is transplanting her this year, at her current complication-free baseline, versus transplanting a future version of her who has had more years for a severe viral infection, a malignancy, or vasculopathy to develop — all of which make transplant itself riskier, not just delay it. Starting HLA typing on her brother and an unrelated donor search now doesn't commit her to a date; it just means we're not starting that process for the first time after something has already gone wrong.
Her brother was HLA-typed the same month and confirmed a full match. Her family, given that result and the framing of transplant timing as a trajectory rather than a binary choice, elected to proceed with transplant referral and scheduling over the following two months rather than deferring further.
Agreed by all three once the reframing was made explicit: the pediatrician's original caution about treating a stable child was answered not by dismissing it but by clarifying what was actually being compared — today's low-risk transplant candidate against a future, higher-risk one, not against an indefinitely stable one.