Importance of genetic diagnosis of DAX-1 deficiency: example from a large, multigenerational family

Entire DAX1 gene deletion in an Indian boy with adrenal hypoplasia congenita

OBJECTIVE

To report a case of Adrenal hypoplasia congenita (AHC) in an Indian boy presenting with adrenal failure in the neonatal period. Molecular diagnosis demonstrated absence of the entire DAX1 gene sequence region.

METHODS

Real-time SYBR Green Polymerase Chain Reaction (PCR) amplification followed by melt curve analysis was the molecular analytical method used. Analysis of the PCR products by Agarose gel electrophoresis was also performed.

RESULTS

Real-time SYBR Green PCR amplification carried out on a 240 bp region of Exon 1 and 320 bp region of Exon 2 of DAX1 gene did not result in any amplification for two independent DNA extractions of the patient sample. The melt curve analysis also failed to show the characteristic melt peaks. Additional analysis of the PCR products performed by Agarose gel electrophoresis of the patient samples did not reveal any DNA bands.

CONCLUSIONS

Inability to amplify two distinct regions located on two distinct exons of the DAX1 gene of the patient sample point to the possible absence of the entire DAX1 gene sequence region in the index patient. Such molecular diagnostic techniques may prove very useful in making a diagnosis as well as for genetic counseling.

Primary adrenal insufficiency caused by a novel mutation in DAX1 gene

Adrenal hypoplasia congenita (AHC) is a rare disorder. The X-linked form is related to mutations in the DAX1 (NROB1) gene. Here, we report a newborn who had a novel hemizygous frameshift mutation in DAX1(c.543delA) and presented with primary adrenal failure that was initially misdiagnosed as congenital adrenal hyperplasia. This report highlights the value of genetic testing for definite diagnosis in children with primary adrenal failure due to abnormal adrenal gland development, providing the possibility both for presymptomatic, and in cases with a sibling with this condition, for prenatal diagnosis.

X-linked adrenal hypoplasia congenita: a novel DAX1 missense mutation and challenges for clinical diagnosis in Africa

Adrenal hypoplasia congenita (AHC) is a rare disease. The X-linked form of AHC is caused by deletions or mutations in DAX1 gene and has a variable clinical presentation. To date, no data on X-linked AHC in central Africa are available. Here, we report a Congolese pedigree with several cases of unexplained deaths of male infants. A careful analysis of the pedigree of this family lead to the recognition of an X-linked inheritance pattern, with subsequent confirmation in a female heterozygous carrier of a DAX1 missense mutation c.1274G>T, (p.Arg425Ile).The diagnosis of this condition remains challenging in a developing country, since the manifestations of AHC overlap with those of the much more frequently occurring infections; darkening of the skin is difficult to evaluate and there is a lack of access to routine endocrinological testing. The diagnosis was eventually made based on the family pedigree, evoking an X-linked inheritance pattern. This illustrates the necessity for medical and clinical genetics to be part of the curriculum of medical school in developing countries.