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[Clinical and genetic analysis of an infant with isolated 17, 20-lyase deficiency]
1Department of Pediatric Endocrinology/Genetics, Xinhua Hospital, Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai Institute of Pediatric Research, Shanghai 200092, China.
Insights
This study details an infant with isolated 17, 20-lyase deficiency, identifying compound heterozygous mutations in the CYP17A1 gene. The findings highlight key clinical and genetic markers for this rare condition.
Area of Science:
- Endocrinology
- Genetics
- Pediatrics
Background:
- Isolated 17, 20-lyase deficiency is a rare disorder affecting steroidogenesis.
- It is caused by mutations in the CYP17A1 gene, leading to impaired cortisol and sex steroid synthesis.
- Affected individuals often present with disorders of sex development.
Purpose of the Study:
- To investigate the clinical, biochemical, and genetic profile of an infant with isolated 17, 20-lyase deficiency.
- To characterize novel mutations within the CYP17A1 gene associated with this condition.
Main Methods:
- Clinical assessment of an 8-month-old infant with 46, XY gonadal dysgenesis.
- Biochemical analysis of hormone levels including progesterone, 17-hydroxyprogesterone, and testosterone.
- Next-generation sequencing (NGS) and Sanger sequencing to identify mutations in the CYP17A1 gene.
Main Results:
- The infant presented with female external genitalia, bilateral inguinal masses, and normal blood pressure.
- Elevated progesterone and 17-hydroxyprogesterone levels were observed, with normal testosterone and other adrenal hormones.
- Compound heterozygous mutations (P409R and a novel V236G) were identified in the CYP17A1 gene.
Conclusions:
- The study identified compound heterozygous mutations P409R and V236G in the CYP17A1 gene in an infant with isolated 17, 20-lyase deficiency.
- The patient exhibited 46, XY gonadal dysgenesis, normotension, and characteristic hormonal imbalances.
- These findings contribute to understanding the genetic basis and clinical presentation of this rare endocrine disorder.
Objective:
To explore the clinical and genetic characteristics of an infant with isolated 17, 20-lyase deficiency.
Method:
The clinical, biochemical and genetic characteristics were analyzed in an 8-month-old infant with 46, XY gonadal dysgenesis who presented predominantly the female external genitalia.
Result:
The infant was referred because of"masses in bilateral inguinal region and 46, XY gonadal dysgenesis". He was normotensive. Laboratory tests revealed elevated levels of progesterone and 17-hydroxyprogesterone. The detailed parameters are as follows: progesterone 29.35(reference range 0.09-1.0)nmol/L, 17-hydroxyprogesterone 10.9(reference range 0.6-2.6)nmol/L, testosterone 0.7(reference range 0.1-3.1)nmol/L, dehydroepiandrosterone sulfate <0.15(reference range 0.80-5.6)mg/L, androstenedione <0.3 (reference range 0.6-3.1) μg/L, luteinizing hormone 6.6(reference range 0.6-1.7)U/L, follicle stimulating hormone 1.8 (reference range 0.5-3.7)U/L, estradiol 37.66(reference range 73.4-146.8)pmol/L. The patient had normal levels of serum sodium, potassium, corticosteroid and plasma adrenocorticotropic hormone. Genomic DNA was extracted from the leukocytes of peripheral blood of the patient and subjected to next generation sequencing (NGS) for testing more than 200 sexual development related genes. Sanger sequencing was used to confirm the results of NGS. Genetic analysis revealed that the patient harbored compound heterozygous mutations of c. 1226C>G (p.Pro409Arg, P409R) and c. 707T>G (p.Val236Gly, V236G) in CYP17A1 gene derived from paternal and maternal allele. V236G was a novel mutation predicted to be pathogenic. The infant was diagnosed as isolated 17, 20-lyase deficiency combined with clinical and molecular characteristics of CYP17A1 gene.
Conclusion:
We have identified the compound heterozygous mutations of P409R and V236G in the CYP17A1 gene in one infant with isolated 17, 20-lyase deficiency. He presented with 46, XY gonadal dysgenesis, normal blood pressure and elevated concentration of progesterone and 17-hydroxyprogesterone.
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