|
|
||||||||
CLINICAL STUDY |
Department of Pediatric Hematology, Oncology and Endocrinology, University Childrens Hospital, Hufelandstr. 55, University of Essen, 45 122 Essen, Germany, 1 Department of Pediatrics, Childrens Hospital of Cologne, Germany, 2 Department of Pediatric Endocrinology, University Childrens Hospital, University of Schleswig-Holstein, Campus Lübeck, Germany, 3 Department of Internal Medicine, Erasmus MC, Rotterdam, The Netherlands and 4 Steroid Research Unit, Center of Child and Adolescent Medicine, Justus Liebig University, Giessen, Germany
(Correspondence should be addressed to A Richter-Unruh; Email: annette.richter-unruh{at}uni-essen.de)
Leydig cell hypoplasia (LCH) is a rare autosomal recessive condition that interferes with normal development of male external genitalia in 46,XY individuals and is caused by inactivating mutations of the LH receptor gene. The clinical and biochemical diagnostic parameters of LCH are not always specific and may therefore show significant overlap with other causes of insufficient testicular steroid biosynthesis. We have studied a 46,XY newborn with completely female external genitalia and palpable testes. Due to an increased basal serum ratio of androstenedione/testosterone, 17ß-hydroxysteroid dehydrogenase type 3 (17ß-HSD 3) deficiency was initially suspected. DNA analysis of the corresponding HSD17B3 gene, however, showed no abnormalities in the entire coding region. In contrast, direct sequencing of the LH receptor gene revealed a novel homozygous single nucleotide insertion in exon 11 (codon A589fs) producing a frame shift in the open reading frame predicting for premature termination of translation 17 amino acids downstream. From the genetic perspective, this mutation represents the first frame shift mutation in the LH receptor gene ever reported to date. From the clinical standpoint, LCH should always be considered in the differential diagnosis as steroid profiles may not be informative. Therefore, molecular genetic analysis should be warranted for androgen biosynthesis defects in all cases.
This article has been cited by other articles:
![]() |
A. P N Themmen An update of the pathophysiology of human gonadotrophin subunit and receptor gene mutations and polymorphisms Reproduction, September 1, 2005; 130(3): 263 - 274. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |