Analysis On Genetic Diagnosis And Clinical Features In 7 Children With Primary Adrenal Insufficiency

Objective To investigate mutations of NR0B1,SF1,ABCD1 and ABCD2 in children with PAI,to diagnose adrenoleukodystrophy(ALD)as soon as possible,customize protocols of monitoring and make HLA-matched.Methods Clinical datas and blood samples were collected in 7 cases with PAI,family members and normal controls from January 2010 to December2016 in the First Affiliated Hospital of Guangxi Medical University.DNA was extracted from the blood of patients,family members and normal controls.All exons of NR0B1 and SF1 were sequenced,and to detect large deletions or duplications of NR0B1 and SF1 multiplex ligation probe amplification(MLPA)were performed in subjects with no mutations of NR0B1 and SF1.All exons of ABCD1 and ABCD2 were sequenced for patients without mutations in NR0B1 and SF1.Very long chain fatty acids(VLCFA)levels were tested in members with mutations of ABCD1,and brain CT and magnetic resonance imaging(MRI)scanings were performed on patients with mutations of ABCD1.Results 7 cases from 3 pedigrees and 2 sporadic cases with childhood-onset are males.All patients showed varying degrees of generalizedhyperpigmentation,higher levels in adrenocorticotropic hormone(ACTH)and lower levels in cortisol.Among them,6 cases were treated with hyperpigmentation,whose electrolyte examinations were preserved in normal range.A boy occurred acute adrenal crisis after birth,included vomiting,diarrhea,dehydration and hypotension,whose electrolyte examinations showed hyponatremia.7 members including 4 patients and 3 female carriers were detected mutations of ABCD1 in 14 members,and all members had no mutations in ABCD2.Three generations from the first family were measured a reported missense mutation(920A>G,Y174C)of ABCD1.The probands including two brothers and their uncle with the mutation who presented PAI were detected higher level in VLCFA(C26:0)and mild white matter demyelination of brain MRI.No nervous system lesions were noted on long-term follow-up,and they didn't make a decision whether they do HLA-matched for hematopoietic stem cell transplantation(HSCT).Mother and grandmother of the probands from the first family were female carriers who were tested a normal and higher VLCFA(C26:0)level respectively,and no nervous system lesions was noted on long-term follow-up.A patient and his mother from the second family were detected a novel missense mutation(1172T>G,L258R)of ABCD1: the boy 4 to 6.5 years of age presented as PAI,followed by blurred vision,developed spastic tetraparesis during 6months of HLA-matched for HSCT,and lost chance of HSCT,whose examination findings showed a higher level of VLCFA(C26:0)and imaging appearances of ALD on brain MRI.His mother,a female carrier,was tested a mild elevation of VLCFA(C26:0)without nervous system lesions on long-term follow-up.2 members were detected mutations of NR0B1 in 14 members,andall members had no mutations in SF1.A patient from the third family was detected a novel insertion mutation of NR0B1(5800-5801 ins G)without hypogonadolropic hypogonadism(HH)and reproductive abnormalities,his mother without PAI and HH was tested the same insertion mutation and a synonymous mutation(5129C>T,C38C)in NR0B1.The rest cases had no mutations of NR0B1,SF1,ABCD1 and ABCD2.Conclusions ChildhoodPAI can be a common manifestation of adrenal hypoplasia congenita(AHC)and Addison-Only of ALD,which are differentiated by genetic analysis of NR0B1,SF1,ABCD1 and ABCD2.Some children with ALD may present as PAI without nervous system lesions during a few years to decades,but may develop cerebral ALD(CALD)in later stage.It is necessary to make a diagnosis of ALD at gene levels as soon as possible,and we should closely observe nervous system lesions(symptoms,signs and brain MRI)and make a preparation for HLA-matched.The novel insertion mutation(5800-5801 ins G)of NR0B1 may cause PAI,and the novel missense mutation(1172T>G,L258R)in ABCD1 may cause ALD.