X-linked hyper-IgM syndrome (XHIGM) is one type of primary immunodeficiency diseases, resulting from defects in the CD40 ligand/CD40 signaling pathways. We retrospectively analyzed the clinical and molecular features of 20 Chinese patients diagnosed and followed up in hospitals affiliated to Shanghai Jiao Tong University School of Medicine from 1999 to 2013. The median onset age of these patients was 8.5 months (range: 20 days–21 months). Half of them had positive family histories, with a shorter diagnosis lag. The most common symptoms were recurrent sinopulmonary infections (18 patients, 90%), neutropenia (14 patients, 70%), oral ulcer (13 patients, 65%), and protracted diarrhea (13 patients, 65%). Six patients had BCGitis. Six patients received hematopoietic stem cell transplantations and four of them had immune reconstructions and clinical remissions. Eighteen unique mutations in
X-linked hyper-IgM syndrome (XHIGM; HIGM1; OMIM: 308230) is one type of primary immunodeficiency diseases (PIDs), resulting from defects in the CD40 ligand/CD40 signaling pathways leading to impairment of immunoglobulin isotype switching in B cells and characterized by recurrent infections in association with markedly decreased serum IgG, IgA, and IgE levels but normal or elevated serum IgM levels [
XHIGM is the most common subtype of hyper-IgM syndromes (affecting about 70% of the patients) [
With diagnosed patients accumulated, people began to analyze the clinical features and mutation characteristics of these patients since 1992 [
Patients in present study were first diagnosed in hospitals affiliated to Shanghai Jiao Tong University School of Medicine or referred from other hospitals and followed up in Shanghai Children’s Medical Center (also affiliated to Shanghai Jiao Tong University School of Medicine) during 1999–2013. A total of 28 candidate patients with HIGM phenotype were recruited. The inclusion criteria were low sera IgG and IgA (2 standard deviations below normal value for age), normal or elevated serum IgM, and compatible infectious events. Patients with secondary immunodeficiency conditions such as HIV or congenital rubella infections, immunosuppressive drug use, or neoplasms were excluded. Then CD154 expression on active T cells was detected by flow cytometry and sequences of
An informed consent was obtained from each patient’s parent or guardian before enrollment in the study. Clinical data were collected from the patients’ medical records, including initial clinical manifestation, onset age, diagnosis age, parental consanguinity, family history of immunodeficiency, recurrent infections, autoimmune diseases or malignancy diseases, vaccination and allergic history, complication, laboratory tests (including immunoglobulin level and lymphocyte subpopulations), and treatments. A total of 5 mL venous blood was collected from patients for pathogen screening and gene sequencing.
Detection of CD154 expression on activated CD4+ T cells was performed by flow cytometry (FACScan, Becton Dickinson, USA) using specific fluorescent-labeled monoclonal antibodies according to the method described previously [
Genomic DNA was isolated from heparinized peripheral blood by using the DP319 kit (Tiangen Biotech Co. LTD., China). The individual exons of
Data were analyzed by SPSS statistical software (version 21.0, SPSS Inc., Chicago, IL). Median and range were used to present the characters of focused variable. Bioinformatics software PolyPhen-2 (
From 1999 to 2013, 20 patients from 19 unrelated families (P2 and P3 are cousins) were diagnosed as XHIGM, considering the clinical manifestations, lab examination, family history, decreased CD154 expression, and the mutation of
Clinical features of patients with XHIGM phenotype.
Patients | Onset age (m) | Diagnosis age (m) | Diagnosis lag (m) | Status | Family history | Time for IVIG | HSCT | Oral ulcer | Otitis media | Recurrent sinopulmonary infections | Recurrent diarrhea | Neutropenia | Other significant events | Special pathogens |
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P1 | 18 | 84 | 66 | L | (+) | 7 y, IR | (+)* | (+) | ||||||
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P2 | 12 | 48 | 36 | 11 y | (+) | 4 y, IR | (+)* | (+) | (+) | (+) | Impetigo; |
VZV | ||
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P3 | 6 | 12 | 6 | D | (+) | 1 y, R | (+) | (+) | (+)* | (+) | (+) | Elevated liver enzyme; |
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P4 | 15 | 20 | 5 | L | (+) | 19 m, IR | (+) | (+) | (+) | Encephalitis*; |
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P5 | 12 | 180 | 168 | D | NA | (+)* | (+) | (+) | SSPE; |
VZV; |
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P6 | 2 | 61 | 59 | 9 y | (+) | 5 y, R | (+) | (+) | (+) | (+) | (+) | BCGitis* |
HBV; |
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P7 | 5 | 54 | 49 | 7 y | 5 y, R | (+) | (+) | (+) | BCGitis* | |||||
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P8 | 4 | 123 | 119 | 27 y | 3 y, R | (+) | (+) | (+) | (+)* | (+) | Arthritis | |||
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P9 | 12 | 48 | 36 | L | (+) | 4 y, IR | (+) | (+) | (+)* | (+) | Chronic kidney disease; |
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P10 | 9 | 60 | 51 | 9 y | 2 y 5 m, R | (+) | (+) | (+)* | (+) | Crohn’s disease | ||||
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P11 | 12 | 192 | 180 | 21 y | NA | (+) | (+) | (+)* | Ulcerative colitis; |
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P12 | 5 | 60 | 55 | 7 y | (+) | 2 y 3 m, IR | (+) | (+) | (+) | (+) | (+) | BCGitis* |
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P13 | 12 | 36 | 24 | D | 3 y, R | (+) | (+) | (+)* | (+) | (+) | Hepatosplenomegaly | Fungus | ||
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P14 | 8 | 105 | 97 | D | 20 m, IR | (+) | (+) | (+)* | (+) | Tuberculous meningitis |
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P15 | 6 | 77 | 71 | 11 y | 7 y, IR | (+) | (+) | (+)* | Perianal abscess; |
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P16 | 0.67 | 60 | 59.33 | 6 y | 3 y 4 m, R | (+) | (+) | (+)* | BCGitis; |
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P17 | 14 | 21 | 7 | D | (+) | NA | (+) | (+)* | BCGitis | |||||
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P18 | 21 | 49 | 28 | 5 y | (+) | NA | (+) | (+) | (+)* | (+) | ||||
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P19 | 3 | 17 | 14 | 2 y | (+) | NA | (+) | (+) | (+) | BCGitis* | ||||
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P20 | 6 | 41 | 35 | 4 y | 3 y, R | (+) | (+) | (+) | (+)* | (+) | ||||
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Total |
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Note: (a) L: lost in followup; D: dead; R: regularly; IR: irregularly; NA: not available; y: year; m: month; IVIG: intravenous immunoglobulin; HSCT: hematopoietic stem cell transplantation; VZV: varicella zoster virus; HBV: hepatitis B virus. (b) *initial symptom.
The most common symptoms of XHIGM patients were recurrent sinopulmonary infections (18 patients, 90%), neutropenia (14 patients, 70%), oral ulcer (13 patients, 65%), and protracted diarrhea (13 patients, 65%). Respiratory and gastrointestinal systems were more frequently affected. Skin (7 patients, 35%), bone and joint system (4 patients, 20%), central nervous system (3 patients, 15%), and urinary system (2 patients, 10%) were also affected (detailed in Table
The median onset age of diarrhea was 12.0 months (range: 20 days to 20 months). Among them, two patients (P10, P11) were diagnosed with inflammatory bowel diseases (IBDs) under enteroscopes, and
Six patients had BCGitis (Table
BCG vaccination-induced adverse drug reactions (ADR) and mycobacterium infections in XHIGM patients.
Patients | Ages | Performances | Treatments |
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P6 | 2 m | BCGitis (ipsilateral axillary lymphadenitis) | Surgery |
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P7 | 2 m | BCGitis (ipsilateral axillary lymphadenitis) | Surgery |
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P12 | 50 d | BCGitis (ipsilateral axillary lymphadenectasis) | Antituberculosis medicine (rifampicin, unregularly) |
35 m | Pulmonary tuberculosis | Antituberculosis medicine (isoniazide + rifampicin + VitB6), antibiotics | |
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P16 | 7 m | BCGitis (ipsilateral axillary lymphadenitis) | Surgery |
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P17 | 2 m | BCGitis (ipsilateral axillary lymphadenitis) | Surgery |
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P19 | 3 m | BCGitis (ipsilateral cervical lymphadenectasis) | Antituberculosis medicine |
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P14 | 8.5 y | Pulmonary tuberculosis, restrictive pulmonary capacity, splenomegaly and lymphadenopathy | Antituberculosis medicine (isoniazide + rifampicin, unregularly), antibiotics, IVIG, thymosin |
10 y | Tuberculous meningitis | Antituberculosis medicine (isoniazide + rifampicin, unregularly) |
Note: IVIG: intravenous immunoglobulin.
Some special manifestations deserved extra attention. P5 was infected by measles and developed subacute sclerosing panencephalitis (SSPE). P11 had
Anemia was found in seven patients (Table
Laboratorial features in XHIGM patients.
Patients ( |
IgG |
IgM |
IgA |
Lowest neutropenia (/ |
Absolute lymphocyte (/ |
Hb (g/L) | PLT (*1000/ |
CD3 (/ |
CD4 (/ |
CD8 (/ |
CD19 (/ |
CD4/CD8 | CD16/56 (/ |
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P1 | <0.33 | 5.07 | <0.07 | 3780 | 2450 | 115 | 320 | NA | NA | NA | NA | NA | NA |
P2 | 2.15 | 1.78 | 0.73 | 580 | 1498 | 90 | 479 | 1261 | 674 | 566 | 203 | 1.20 | 234 |
P3 | 0.39 | 0.92 | 0.23 | 1390 | 2110 | 111 | 444 | 1139 | 635 | 433 | NA | 1.32 | NA |
P4 | 0.08 | 9.48 | <0.22 | 26000 | 3600 | 83 | 679 | 1116 | 572 | 486 | 756 | 1.18 | 1152 |
P5 | <0.33 | 2.73 | <0.07 | 900 | 3402 | 156 | 316 | 2007 | 700 | 1204 | 388 | 0.58 | 173 |
P6 | <0.33 | 2 | <0.07 | 139 | 1470 | 100 | 293 | 1021 | 786 | 182 | 392 | 4.32 | 42 |
P7 | 1.77 | 3.96 | <0.24 | 360 | 5364 | 126 | 175 | 4076 | 2789 | 1180 | 912 | 2.36 | 375 |
P8 | 1.5 | 9.21 | 0.07 | 990 | 1285 | 100 | 184 | 1052 | 520 | 563 | 188 | 0.92 | 69 |
P9 | <1.87 | 1.87 | <0.03 | 306 | 4618 | 59 | 311 | 4248 | 1662 | 2424 | 222 | 0.68 | 111 |
P10 | 3.59 | 0.74 | 0.7 | 330 | 1350 | 81 | 243 | 999 | 729 | 189 | 346 | 3.86 | 28 |
P11 | 1.81 | 4.1 | 0.35 | 2214 | 1140 | 68 | 92 | 949 | 307 | 485 | 144 | 0.63 | 40 |
P12 | 0.32 | 3.65 | <0.07 | 377 | 6200 | 120 | 673 | 4625 | 2263 | 1761 | 1389 | 1.29 | 174 |
P13 | 1.75 | 2.67 | <0.24 | 190 | 5600 | 117 | 143 | 4178 | 2610 | 1349 | 1277 | 1.93 | 140 |
P14 | 2 | 3.56 | 0.52 | 200 | 1500 | 86 | 451 | 779 | 393 | 282 | 663 | 1.39 | 57 |
P15 | 1.21 | 11.7 | 0.24 | 1800 | 2778 | 19 | 325 | 2000 | 909 | 949 | 541 | 0.96 | 225 |
P16 | 0.45 | 2.24 | 0.55 | 2590 | 3360 | 117 | 335 | 2218 | 1277 | 605 | 706 | 2.14 | 370 |
P17 | <0.33 | 1.98 | <0.07 | 2000 | 6300 | 108 | NA | 2553 | 1323 | 1017 | 3024 | 1.24 | 504 |
P18 | 1.11 | 8.47 | 0.02 | 720 | 6140 | 112 | 476 | 4851 | 2579 | 1842 | 737 | 1.40 | 368 |
P19 | 0.199 | 0.77 | <0.22 | 786 | 3144 | 96 | 633 | 2075 | 1100 | 1163 | 566 | 0.95 | 409 |
P20 | 0.27 | 3.8 | 0.42 | 440 | 3188 | 98 | 656 | 2295 | 1243 | 638 | 542 | 1.95 | 223 |
Note: NA: not available.
The median serum IgM concentration was 3.15 g/L (range: 0.74–11.7 g/L). Seventeen patients had elevated IgM levels and three patients had normal IgM levels. Serum IgG levels were uniformly decreased. IgA levels were reduced in the majority of patients.
Lymphocyte counts were generally normal. Three patients (P5, P9, and P11) exhibit significantly decreased CD4/CD8 ratio. They all had severe clinical symptoms and the decreased ratio reflected the impaired cellular immunity. P5 had measles infection, leading to SSPE, and died within one year. P11 had
Eighteen unique mutations were identified in 20 patients from 19 unrelated families (P2 and P3 were cousins and they had the same mutation. Besides, P12 and P16 had the same mutation). Among the 19 families, we found 7 deletions, 6 missense mutations, 2 nonsense mutations, 2 splice site mutations, and 2 insertions (Table
Mutations in
Patients ( |
Genomic DNA mutation (NC_000023.10) | cDNA mutation (NM_000074.2) | Predicted effect on protein (NP_000065.1) | Affected domain | Exon/intron | CD40L expression | References |
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P1 | g.175delC | c.175delC | p.Gln35ArgfsX36 | TM | Exon 1 | NA | |
P2 | g.186delG | c.186delG | p.Ser39GlnfsX48 | TM | Exon 1 | 0.09% | |
P3 | g.186delG | c.186delG | p.Ser39GlnfsX48 | TM | Exon 1 | 0.31% | |
P4 | g.6196g>a (IVS2-1g>a) | Skipping exon3 | Skipping exon3 | Intron 2 | NA | ||
P5 | g.8181_8182insGT | c.420_421insGT | p.Asp117ValfsX128 | ECU | Exon 4 | 0.02% | |
P6* | g.10952G>C | c.499G>C | p.Gly167Arg | TNFH | Exon 5 | 0.27% | [ |
P7* | g.11160C>A | c.707C>A | p.Ser236X | TNFH | Exon 5 | 0.75% | [ |
P8 | g.11069_11072delCTCA | c.616_619delCTCA | p.Leu206GlufsX240 | TNFH | Exon 5 | 0.80% | |
P9* | g.12090C>A | c.654C>A | p.C218X | TNFH | Exon 5 | NA | [ |
P10* | g.10861a>g (IVS4-2a>g) | c.482delTGTTACAG | Exon5 absent | TNFH | Intron 4 | 0.31% | [ |
P11 | g.100C>T | c.100C>T | p.Pro10Ser | IC | Exon 1 | 4.55% | |
P12* | g.2091_2094delTAGA | c.158_161delTAGA | p.Ile53LysfsX65 | ECU | Exon 2 | 0.01% | [ |
P13 | g.11220T>C | c.767T>C | p.Phe256Ser | TNFH | Exon 5 | 0.53% | |
P14 | g.11067T>C | c.686T>C | p.Leu205Ser | TNFH | Exon 5 | 1.78% | |
P15 | g.173_189delcccagatgattgggtca | c.173_189delcccagatgattgggtca | p.Thr34CysfsX42 | TM | Exon 1 | 0.42% | |
P16* | g.2091_2094delTAGA | c.158_161delTAGA | p.Ile53fsLysX65 | ECU | Exon 2 | NA | [ |
P17 | g.11075G>C | c.694G>C | p.Ala208Pro | TNFH | Exon 5 | NA | |
P18 | g.10986delG | c.605delG | p.Cys178PhefsX190 | TNFH | Exon 5 | NA | |
P19 | g.10882_10883insA | c.501_502insA | p.Gly144ArgfsX158 | TNFH | Exon 5 | NA | |
P20* | g.10871T>C | c.490T>C | p.Trp140Arg | TNFH | Exon 5 | NA | [ |
Note: *mutation that has been reported. IC: intracytoplasmic domain; TM: transmembrane region; ECU: extracellular unique domain; TNFH: tumor necrosis factor homology domain; NA: not available.
Five patients had died (Table
Fifteen patients (75%) received intravenous immunoglobulin (IVIG) treatment (Table
Six patients received HSCTs and the median age at transplantation was 6 years old. Four patients received hematopoietic stem cells from HLA-identical unrelated donors and they had clinical remissions and were followed up from months to 6 years. The other two patients had HLA-half identical sibling donors and died from severe infections (Table
Transplantation strategies for the six XHIGM patients.
Patients | Age at diagnosis (y) | Age at HSCT (y) | Pretransplantation status | Donors | Complications | Outcomes |
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P3 | 1 | 2 | Oral ulcer, elevated liver enzyme, neutropenia | Haploidentical sibling | VOD, paralytic ileus, pulmonary infection, DIC | Died |
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P6 | 5 | 6.5 | Gingivitis, neutropenia | HLA-identical unrelated donor | GVHD Grade I, |
9 y, clinical remission. |
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P8 | 10.25 | 21 | Oral ulcer | HLA-identical unrelated donor | GVHD Grade III, |
27 y, clinical remission. Pneumonia once a year within the first two years after HSCT. Free of IVIG. |
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P10 | 5 | 6 | Oral and perianal ulcer, abdominal pain, diarrhea, fever, prolonged APTT, anemia | HLA-identical unrelated donor | GVHD Grade I, |
9 y, clinical remission. |
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P13 | 3 | 4.5 | Oral ulcer, diarrhea, neutropenia | Haploidentical sibling | Sepsis | Died |
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P20 | 3.4 | 4.6 | Oral ulcer, neutropenia | HLA-identical unrelated donor | GVHD Grade II, |
4 y 10 m, clinical remission. |
Note: HSCT: hematopoietic stem cell transplantation; VOD: hepatic venoocclusive disease; DIC: disseminated intravascular coagulation;
GVHD: graft-versus-host disease; ADH: antidiuretic hormone; IVIG: intravenous immunoglobulin.
This study described the clinical features of Chinese XHIGM patients. Respiratory and gastrointestinal systems were more frequently affected. Skin, bone and joint system, central nervous system, and urinary system were also involved. In this study, two patients (P9 and P11) developed chronic kidney diseases. Cardiovascular disease, infections, and nonsteroidal anti-inflammatory drugs (NSAIDs) are accepted risk factors for causing chronic kidney disease [
Opportunistic infections, especially
Some recent discoveries may help to elucidate the susceptibility to mycobacterial infections in XHIGM patients. Hayashi’s results indicated that CD40-CD154 signaling might be an important step in host immune response against
Mutations of
Mutation types in
Reports | Year | Number of mutations | Missense (%) | Nonsense (%) | Deletion (%) | Insertion (%) | Splice site (%) |
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Nonoyama et al. [ |
1997 | 13 | 30.8 | 23.1 | 23.1 | 0 | 23.1 |
Seyama et al. [ |
1998 | 28 | 32.1 | 17.9 | 7.2 | 14.3 | 32.1 |
Lee et al. [ |
2005 | 61 | 18.0 | 24.6 | 21.3 | 11.5 | 24.6 |
Winkelstein et al. [ |
2003 | 54 | 22.2 | 18.5 | 24.1 | 11.1 | 24.1 |
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Cabral-Marques et al. [ |
2014 | 26 | 34.6 | 26.9 | 11.5 | 7.7 | 11.5 |
Some possible mutation hotspots have been identified. Notarangelo et al. [
In this study, we identified two splice site mutations (P4: IVS2−1 g
Six patients had missense mutations in this study. From data published in CD40Lbase (updated to 2011), the most frequent amino acid substitutions were Leu to Ser/Pro, Thr to Met, Gly to Arg, and Ala to Asp/Glu. Thusberg and Vihinen [
Four missense mutations were novel. Mutation in P14 (p.Leu205Ser) changed the conserved hydrophobic residue into a hydrophilic residue. Proline was involved in the mutations in P11 (p.Pro10Ser) and P17 (p.Ala208Pro). Proline is the only amino acid forming a ring with the backbone and bends the main chain of the protein in a characteristic way. Proline is a known breaker of secondary structures. The substitution in the two patients would profoundly change structure and functions of the protein. A p.Ala208Asp mutation was identified in an XHIGM patient and reported in 2002 [
Effects of the four novel point mutations were analyzed by using bioinformatics software PolyPhen-2 [
Two patients had nonsense mutations at codon 236 and codon 218, both of which were already reported [
Nine patients had insertion/deletion mutations, all changing the reading frames and leading to large changes of the protein structure. P12 and P16 were from unrelated families and they had the same mutation (g.2091_2094delTAGA, c.158_161delTAGA, p.Ile53fsX13). This mutation had been reported in at least another 6 unrelated patients and was the fifth common mutation position in the CD40Lbase. The 4 deleted nucleotides were very close to the acceptor splice site of intron 1 and were flanked by repeat sequences, suggesting that these mutations might be caused by slipped mispairing mechanisms. The frame shift deletion led to a premature stop codon within the extracellular unique domain. P2 and P3 were cousins and they had the same mutation (g.186delG). The deletion in exon 1 led to a premature stop codon in the transmembrane domain.
In conclusion, we retrospectively investigated the clinical, immunological, and molecular features of 20 Chinese XHIGM patients diagnosed and followed up in our center. We identified 18 unique mutations in
None of the authors has any potential financial conflict of interests related to this paper.
Lin-Lin Wang and Wei Zhou are co-first authors and had equal contributions to the study.
The authors express their gratitude to all the patients and their families for their kindness for permission and cooperation. The authors are also grateful to Koon-Wing Chan, Department of Paediatrics and Adolescent Medicine, The University of Hong Kong, for his kind advice on sequence analysis.