Difficulties in diagnosis and treatment of 5alpha-reductase type 2 deficiency in a newborn with 46,XY DSD.
Horm Res Paediatr
; 74(1): 67-71, 2010.
Article
in En
| MEDLINE
| ID: mdl-20395661
ABSTRACT
BACKGROUND/AIMS:
Steroid 5alpha-reductase deficiency (MIM*607306) caused by mutations in the SRD5A2 gene is characterized by a predominantly female phenotype at birth and significant virilization at puberty. The undermasculinization at birth results from low dihydrotestosterone (DHT) levels during fetal development as the type 2 isoenzyme activity is reduced. In puberty, when the type 1 isoenzyme activity increases, significant virilization occurs. Most 46,XY individuals with 5alpha-reductase 2 deficiency develop a male gender identity. CASE REPORT ANDRESULTS:
We present a case with a predominantly female phenotype and ambiguous external genitalia but a normal 46,XY karyotype. Plasma steroid analysis after beta-hCG stimulation at 8 days of age revealed a steroid profile estimated as normal with a testosterone (T)/DHT ratio of 9.5 initially misleading to the exclusion of 5alpha-reductase deficiency. However, mutation analysis of the SRD5A2 gene revealed a homozygote point mutation (Leu55Gln) confirming the diagnosis of 5alpha-reductase deficiency. A male phenotype was successfully achieved by hormone treatment with T and DHT after diagnosing 5alpha-reductase deficiency and a masculinization operation. As a side effect skeletal age accelerated temporarily.CONCLUSION:
In individuals with predominantly female phenotype and suspected 5alpha-reductase deficiency, a T/DHT ratio during the neonatal period >8.5 might point to 5alpha-reductase deficiency. After confirmation of the diagnosis by molecular analysis of the SRD5A2 gene, a satisfactory change to a male phenotype can be achieved by hormone treatment preceding surgery.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Dihydrotestosterone
/
Testosterone
/
3-Oxo-5-alpha-Steroid 4-Dehydrogenase
/
Gonadal Dysgenesis, 46,XY
Type of study:
Diagnostic_studies
Limits:
Female
/
Humans
/
Male
/
Newborn
Language:
En
Journal:
Horm Res Paediatr
Journal subject:
ENDOCRINOLOGIA
/
PEDIATRIA
Year:
2010
Document type:
Article
Affiliation country: