Environmental exposure during pregnancy and the risk of childhood allergic diseases

Background Allergic diseases are one of the most common and important diseases that can exert hazardous effects on chil-dren's health.The prevalence of allergic diseases in childhood is gradually increasing all over the world in recent decades.Known causes of these diseases include anomalous immune responses and allergic inflammatory reactions,but the causes of allergic diseases in childhood are complex.Data sources PubMed,Cochrane Library,Embase and Web of Science were searched for articles focusing on environmen-tal exposure during pregnancy and the risk of childhood allergic diseases,including asthma and atopic dermatitis,and the possible underlying mechanism.Results In terms of environmental factors,allergice diseases in childhood are closely related to environmental chemical expo-sure during pregnancy,including bisphenols,phthalates acid esters,perfuorochemicals,polybrominated diphenyl ethers,and polychlorinated biphenyls.However,allergic diseases in childhood are also closely associated with maternal dietary nutrition,maternal intake of drugs,such as acetylsalicylic acid(aspirin),paracetamol and antibiotics,and maternal lifestyle.Conclusions Several harmful environmental factors during pregnancy can result in the interruption of the function of helper T cells(Th1/Th2),cytokines and immunoglobulins and may activate allergice reactions,which can lead to allergic diseases during childhood.

Eight novel mutations in the ABCD1 gene and clinical characteristics of 25 Chinese patients with X-linked adrenoleukodystrophy

Background:X-linked adrenoleukodystrophy(X-ALD)is a fatal neurodegenerative disease caused by mutations in the adenosine triphosphate-binding cassette D1(ABCD1)gene.This study aimed to retrospectively investigate the clinical characteristics of 25 patients with X-ALD including members of large pedigrees,to analyze ABCD1 gene mutations,the effect of gene novel variants on ALD protein(ALDP)structure and function,and to expand gene mutation spectrum of Chinese patients.Methods:Twenty-five male patients diagnosed with X-ALD were enrolled in this study.The clinical characteristics of the patients were retrospectively summarized by reviewing medical records or telephone consultation.ABCD1 gene mutations were analyzed.The pathogenicity of novel missense variants was analyzed using cobalt constraint-based multiple protein alignment tool,polymorphism phenotyping,sorting intolerant from tolerant,Align-Grantham variation and Grantham deviation,and Swiss-Program Database Viewer 4.04 software,respectively.Results:Childhood cerebral form ALD(CCALD)is the most common phenotype(64%)in the 25 patients with X-ALD.The progressive deterioration of neurological and cognitive functions is the main clinical feature.The demyelination of the brain white matter and elevated plasma very long chain fatty acids(VLCFAs)were found in all patients.Different phenotypes were also presented within family members of the patients.Twenty-two different mutations including 8 novel mutations in the ABCD1 gene were identifi ed in the 25 patients.Of the mutations,63.6%were missense mutations and 34.8%located in exon 1.The amino acid residues of three novel missense mutations in eight species were highly conserved,and were predicted to be"probably"damaging to ALDP function.The other five novel mutations were splice,nonsense,deletion or duplication mutations.Conclusions:CCALD is the most common phenotype(64%)in our patients with X-ALD.Eight novel mutations in the ABCD1 gene identifi ed are disease-causing mutations.Brain magnetic resonance imaging and plasma VLCFA determination should be performed for the patients who present with progressive deterioration of neurological development.