Objective:To study the clinical features of transthyretin amyloid polyneuropathy (ATTR-PN) caused by Ser77Tyr mutation.Methods:The clinical data of a patient with ATTR-PN caused by Ser77Tyr mutation, admitted to our hospital from Department of Neurology, Mindong Hospital Affiliated to Fujian Medical University, were retrospectively analyzed. Literature on patients with ATTR-PN caused by Ser77Tyr mutation in Pubmed, Web of Science, CNKI and Wanfang databases and those with ATTR-PN caused by Val30Met mutation in Pubmed and Web of Science were searched and screened, and clinical characteristics of these patients were extracted. The differences of clinical characteristics among patients with ATTR-PN caused by Ser77Tyr or Val30Met mutations were compared.Results:(1) Transthyroxin ( TTR) gene Sanger sequencing results showed Ser77Tyr heterozygous pathogenic mutation; Congo red staining of biopsy sample in the patient 2.5 years after onset showed amyloid deposition. (2) Seventy-eight patients with ATTR-PN caused by Ser77Tyr mutation were summarized, they mostly had onset at 50-60 years old; male patients had higher incidence (74.4%); most patients (78.0%) had positive family history; most patients had sensory symptoms as initial symptom (72.0%), which gradually progressed to extensive peripheral nerve involvement and combined with widespread heart damage (96.4%) over several years; electrophysiological examination mainly showed axonal damage and carpal tunnel syndrome; the tissue biopsy had high positive rate(84.8%). (3) There were 192 and 96 patients with ATTR-PN caused by early-onset and late-onset Val30Met mutations, respectively; compared with patients with ATTR-PN caused by early-onset Val30Met mutation, patients with ATTR-PN caused by Ser77Tyr mutation had significantly higher incidence of deep sensory disturbance (28.6% vs. 58.5%, P<0.05). Compared with patients with ATTR-PN caused by late-onset Val30Met mutation, patients with ATTR-PN caused by Ser77Tyr mutation had increased incidence of mild sensory disturbance (56.3% vs. 75.0%) and decreased incidence of limb weakness (65.6% vs. 48.3%), with significant differences ( P<0.05). ATTR-PN patients caused by Ser77Tyr mutation had significantly higher incidence of carpal tunnel syndrome than ATTR-PN patients caused by early-onset and late-onset Val30Met mutations (75.4% vs. 10.8% and 25.0%) and significantly higher incidence of cardiac damage than ATTR-PN patients caused by early-onset Val30Met mutation (96.4% vs. 80.5%, P<0.05). Conclusion:Ser77Tyr mutation has some distinctive clinical features: relatively balanced damage of large and small fibers, prominent carpal tunnel syndrome, and obvious heart disease; early identification of these features and administration of tissue biopsy and gene detection are helpful for early diagnosis.

Objective:To analyze the clinical features of adult deficiency of adenosine deaminase 2 (DADA2) with neurological impairment.Methods:The clinical data of an adult DADA2 patient with concurrent neurological damage who visited the Department of Neurology, Mindong Hospital Affiliated to Fujian Medical University on September 18, 2023 were retrospectively analyzed. The clinical studies or case reports related to adult DADA2 with nervous system involvement from Pubmed, CNKI, and Wanfang databases were retrieved, and the clinical characteristics of adult DADA2 with neurological damage were summarized. The clinical data of children with nervous system involvement in the same study cohorts were also collected, and the clinical features of DADA2 between adults and children were compared.Results:The patient was a 30-year-old male, mainly presenting with manifestations of livedo reticularis, stroke and spastic paraplegia. Genetic testing showed a compound heterozygous mutation in the adenosine deaminase 2 ( ADA2) gene, and brain MRI showed lacunar infarcts in the right basal ganglia and thalamus, hypertrophic inferior olivary degeneration. The literature review found that a total of 22 adult DADA2 patients with neurological damage have been reported, with a onset age of 25 (19, 29) years. Stroke was the most common feature of neurological involvement in patients with this disease (17/22, 77.3%), followed by cranial nerve damage (7/22, 31.8%) and limb nerve damage (8/22, 36.4%). After the treatment with tumor necrosis factor (TNF) inhibitors, the condition of 17/20 patients remained stable or improved. Compared with pediatric DADA2 patients with concurrent neurological damage, the incidence of fever [12/22(54.5%) vs 48/59(81.4%)], arthritis [6/22(27.3%) vs 34/59(57.6%)], and hematological abnormalities [4/22(18.2%) vs 28/60(46.7%)] in adult DADA2 patients was significantly reduced, and the difference was statistically significant (χ 2=5.998, 5.907, 5.489, respectively, all P<0.05). Conclusions:Adult DADA2 with concurrent neurological damage generally onset in early adulthood, mainly manifested as stroke, and may also be accompanied by peripheral nerve damage. Adult patients have fewer systemic symptoms than children, and timely treatment with TNF inhibitors can lead to better outcomes.