A rare genetic condition caused Danni-Lea Sandland to suffer from thrush all over her body since birth. The 30-year-old mother of two, from Skegness, has spent decades enduring the fungal infection, which causes itching, painful rashes, white discharge, and stinging during sex and urination. “My mum tried all sorts [to cure it],” she said. “She was constantly taking me to the doctors but no one knew what it was and why it wasn’t clearing up.”
As a child and young woman, Danni-Lea used antifungal creams, but they never fully cleared the infection. Doctors repeatedly questioned whether she was taking the medication correctly. “I had it constantly for years, I’d always use creams but it wouldn’t clear up,” she recalled. The chronic thrush led to severe dental problems: her gums and mouth became so painful that brushing her teeth became unbearable, and by the age of 24 she had lost all her teeth and required a full set of dentures.
There was a brief period of relief in her teens when she began taking statins – cholesterol-lowering drugs that can also reduce inflammation and bacterial infections. Her symptoms eased for around seven years. But statins are not recommended for women trying to conceive, and when Danni-Lea became pregnant at 23, the thrush returned “in full force” and began to affect her nails.
Her son, Clay, now eight, started showing similar symptoms soon after birth. It began on one of his thumbs but spread quickly to his other fingers. He was originally diagnosed with psoriasis and given a cream, but the condition worsened. “We were really determined on getting answers for Clay,” Danni-Lea said. That determination led her to apply for the Really TV show The Really Bad Skin Clinic, hosted by consultant dermatologist Dr Emma Craythorne. Clay appeared in the show’s ‘Kids Special’ in 2021, and both he and his mother were eventually diagnosed with STAT-1 gain of function (GOF) – a rare genetic disorder that causes the immune system to be chronically overactive.
STAT‑1 Gain of Function: What the Condition Involves
STAT‑1 GOF is a genetic disorder caused by mutations in the STAT1 gene, which normally helps regulate immune responses. In people with the condition, the STAT1 protein is overactive, leading to a dysfunctional immune system that both fails to fight infections effectively and mistakenly attacks the body’s own healthy tissues. The condition is autosomal dominant, meaning only one copy of the mutated gene is needed to cause it, though new spontaneous mutations can also occur.
The hallmark symptom is chronic mucocutaneous candidiasis (CMC) – persistent or recurrent fungal infections with Candida that affect the mouth, skin, nails, and other mucous membranes. More than 90% of individuals with STAT‑1 GOF suffer from CMC, which explains Danni-Lea’s lifelong battle with thrush over her entire body. Beyond fungal infections, patients are prone to bacterial and viral infections, including recurrent respiratory infections and skin infections.
A significant feature of the disorder is the development of autoimmune diseases. Danni-Lea already has type 1 diabetes and hypothyroidism – both common autoimmune comorbidities in STAT‑1 GOF. Other autoimmune conditions frequently seen include autoimmune hemolytic anaemia, autoimmune thrombocytopenia, and disorders that can mimic IPEX syndrome (leading to severe intestinal damage, weight loss, and malnutrition). Autoimmune hepatitis, vitiligo, psoriasis, and alopecia have also been reported. The chronic inflammation and pain from persistent infections can cause severe dental deterioration – as Danni-Lea experienced – and the condition carries an increased risk of squamous cell carcinoma of the skin and gastrointestinal tract, as well as cerebral aneurysms in around 6% of patients.
Diagnosis requires genetic testing to identify mutations in the STAT1 gene. Danni-Lea and Clay received their diagnoses after being seen by specialists on the TV show, highlighting how the condition’s rarity often leads to misdiagnosis or years of unanswered questions. It is believed that over 400 people worldwide have been identified with STAT‑1 GOF, though the actual number may be higher due to underdiagnosis.
Current Treatment and Advocacy
Management of STAT‑1 GOF is complex. Oral or intravenous antifungal medications are essential for controlling the thrush infections, and patients often need long-term prophylactic treatment to prevent recurrence. Danni-Lea was initially given antifungal creams, but they were ineffective because the underlying immune dysfunction was not addressed. For autoimmune symptoms, doctors may prescribe corticosteroids and other immunosuppressants, as well as hormone replacement therapies such as insulin for diabetes and thyroid hormone for hypothyroidism.
More recently, drugs that block Janus kinase (JAK) pathways – such as tofacitinib and ruxolitinib – have shown promise in reducing both the autoimmunity and the chronic Candida infections by dampening the overactive STAT1 signalling. For severe, life-threatening cases that do not respond to conventional treatments, haematopoietic stem cell transplantation (HSCT) considered potentially curative, though it carries significant risks including graft failure, infection, and mortality. Younger patients tend to have better outcomes. Danni-Lea and her son are currently receiving home infusions and are scheduled for stem cell transplants and chemotherapy – the latter used as a conditioning regimen to clear their bone marrow before the transplant.
Despite the severity of her condition, Danni-Lea is determined to raise awareness. She described the emotional toll: “I worked in bars and when I was using my hands serving, I wore gloves because I was embarrassed by them. People looked at me like I was contagious, especially if it was on my hands.” She began to order shopping online, wore a face mask often, and avoided going out. The constant vaginal thrush has caused internal scarring, making sex painful. “I avoid sex as much as I can,” she said. “I feel guilty every night but [my partner is] really understanding. He’s never said anything about it, he’s just accepted how it is.”
Reflecting on the diagnosis, she said: “It was a relief getting diagnosed, but I didn’t realise there’s no actual treatment plan because it’s such a rare condition.” She now wants other people to recognise the signs of STAT‑1 GOF and understand that it is not contagious. “People think it’s thrush and that’s contagious, but this isn’t the same strain. We can’t pass it onto anyone,” she stressed. “It’s done irreversible damage to my body.”