Low frequency of the CYP21A2 deletion in ethnic Chinese (Taiwanese) patients with 21-hydroxylase deficiency

Congenital adrenal hyperplasia (CAH) is a common autosomal recessive disorder which causes more than 90% of CAH cases due to defects in the steroid 21-hydroxylase gene (CYP21A2). The frequency of large mutations was determined in 200 ethnic Chinese (i.e., Taiwanese) CAH patients belonging to 200 families with different clinical forms of CYP21A2 deficiency over 10 years of molecular diagnoses. For a large-gene deletion (or conversion) and the CYP21A2 deletion identification, a PCR product covering the TNXB gene and the 5′-end of the CYP21A2 gene with TaqI endonuclease digestion was analyzed by electrophoresis on agarose gels. For CYP21A2 mutational analysis, secondary PCR amplification of the amplification-created restriction site method was applied. From the results of the analysis, we found that large-gene deletions (or conversions) occurred in 7.5% of the alleles including three different types of the chimeric CYP21A1P/CYP21A2 genes and the haplotype of IVS2-12A/C>G in combination with the 707-714del mutation (without the P30L mutation). The CYP21A2 deletion occurred in 2.0% of the alleles which contained three types of the chimeric TNXA/TNXB genes with two novel ones. We concluded that the CYP21A2 deletion in the ethnic Chinese (Taiwanese) patients exhibits a low occurrence, with the haplotype of the IVS2-12A/C>G in combination with the 707-714del mutation (without the P30L mutation) being prevalent among large gene deletions or conversions.     

Duplication of 111 bases in exon 1 of the CYP21 gene is combined with deletion of CYP21P-C4B genes in steroid 21-hydroxylase deficiency

Congenital adrenal hyperplasia (CAH) is a common autosomal recessive disorder mainly caused by defects in the steroid 21-hydroxylase (CYP21) gene. A 9.3-kb fragment generated by NdeI and AseI digestion by Southern blot analysis indicated that a consequence of deletion of the C4-CYP21 repeat module was the production of a distinct chimeric CYP21P/CYP21 molecule. In the present study, we report a novel CYP21 genotype in two CAH families in which the gene appeared as 9.4- and 3.3-kb fragments by TaqI digestion, rather than as a chimeric gene. From the analysis of PCR amplification patterns and DNA sequencing, we found that there was a duplication of 111 bases from codons 21 to 57 inserted at codon 58 in exon 1 of the CYP21 gene. In addition, codon 21 in the repeated sequence changed from TGG to AGG. Furthermore, this novel CYP21 gene present in both CAH families showed no mutations at IVS2-12A/C>G, 707-714delGAGACTAC, and P30L. Interestingly, the 5' end region of these two CYP21 genes showed the sequence of the CYP21P gene at nucleotides (nt) -103, -110, -123, and thereafter. Our data suggest that these two CYP21 genes are caused by deletion of the CYP21P, XA, RP2, and C4B genes. Possibly, the additional 111-base duplicated coding sequence may be generated by multiple intergenic recombinations, while there seems to be no relationship with deletion of the CYP21P-C4B regions.     

The chimeric<Emphasis Type="Italic"> CYP21P/CYP21</Emphasis> gene and 21-hydroxylase deficiency

The chimeric CYP21P/CYP21 gene is a consequence of a 26- or 32-kb deletion in the C4-CYP21 repeat module of CYP21P, tenascin A (XA), serine/threonine nuclear protein kinase (RP2), and the C4B and CYP21 genes in congenital adrenal hyperplasia (CAH) with steroid 21-hydroxylase deficiency. To date, there have been three distinct chimeras found in CAH patients in ethnic Chinese. Initiation for production of these molecules is proposed to be chi-like sequences and a minisatellite consensus existing in several noncoding regions in CYP21 genes. These molecules have the 5 end of the CYP21P-specific sequence in common but differ in the 3 end of CYP21-specific genes. In addition, there appears to be a 3.2-kb fragment generated by Taq I digestion, which leads to allele dropout in PCR amplification for detecting the aberrant splicing site of the IVS2 –12A/C>G mutation at nucleotide (nt) 655 in the CYP21 gene. Therefore, the chimeric CYP21P/CYP21 cannot be detected by conventional methods. It has been demonstrated that a PCR product amplified with allele-specific primers covering tenascin B (TNXB) to the 5 end of the CYP21 gene combined with Southern analysis by Ase I and Nde I digestion may be used for identifying the chimera in the CYP21 gene.     

The residue E351 is essential for the activity of human 21-hydroxylase: evidence from a naturally occurring novel point mutation compared with artificial mutants generated by single amino acid substitutions

Congenital adrenal hyperplasia (CAH) [OMIM 201910] is a group of autosomal recessive disorders, caused in 90–95% of cases by a deficiency of steroid 21-hydroxylase due to mutations in the CYP21A2 gene. The functional and structural effects of a novel rare missense mutation (E351K) in CYP21A2 found in a male patient with simple virilizing CAH were studied. The novel E351K point mutation is located in the ERR triad of the 21-hydroxylase. The ERR triad is a glutamine–arginine–arginine motif conserved in all cytochrome P450 sequences. The glutamate and first arginine residue are invariant in all P450 cytochrome enzymes, whereas the second arginine residue is present as arginine, histidine, or asparagine. Although the ERR triad is involved in some way to heme binding by the cytochrome P450 monooxygenases, the E351K mutation leads to severe but not complete loss of CYP21 enzyme activity. The functional analysis in COS-7 cells revealed a reduced conversion of 17-hydroxyprogesterone to 11-deoxycortisol of 1.1±0.5% (SD) and of progesterone to 11-deoxycorticosterone of 1.2±0.3% of wild-type activity. Analyzing the artificial mutants (E351D, E351I) of the E351 residue did not show a restoration of the in vitro 21-hydroxylase activity. These effects could be readily explained by structural changes induced by the mutations, which were rationalized by a three-dimensional-model structure of the CYP21 protein. The combination of in vitro enzyme function and computerized protein analysis of the E351 residue of the CYP21 protein provides experimental evidence for the ERR triad being a fundamental structural element of cytochrome P450 enzymes.     

A rare TaqI polymorphism in a human complement C4 gene is caused by an additional restriction site in the first intron.

We studied the configuration of the complement C4/CYP21 (steroid 21-hydroxylase) region of the human major histocompatibility complex in patients suffering from congenital adrenal hyperplasia (CAH) and in the general population in The Netherlands, using C4 and CYP21 probes and the restriction enzymes TaqI and Bg/II. We found a rare TaqI 3.9-kb restriction fragment in the mother of a CAH patient, and present evidence that this polymorphism is caused by an additional restriction site in the first intron of a complement C4 gene.     

CYP21 mutations and congenital adrenal hyperplasia

Congenital adrenal hyperplasia (CAH) is a common autosomal recessive disorder caused mainly by defects in the steroid 21-hydroxylase (CYP21) gene. More than 90% of CAH cases are caused by mutations of the CYP21 gene on chromosome 6p21.3. The wide range of CAH phenotypes is associated with multiple mutations known to affect 21-hydroxylase enzyme activity. To date, 56 different CYP21 mutations have been reported, mostly point mutations, but small deletions or insertions have been described too, as well as complete gene deletions. Fifteen mutations, constituting 90-95% of alleles, are derived from intergenic recombination of DNA sequences between the CYP21 gene and the highly homologous CYP21P pseudogene, while the remaining are spontaneous mutations. A reliable and accurate detection of CYP21 mutations is not only important for clinical diagnosis, but also for carrier detection as there is a high variability in the basal level of 17-hydroxyprogesterone between normal and heterozygous individuals. Several strategies based on polymerase chain reaction (PCR)-driven amplification with allele-specific oligonucleotides to the CYP21 gene have been developed. It has been demonstrated that one reaction for PCR amplification of the CYP21 gene and the chimeric CYP21P/CYP21 gene using mixed primers in combination with nested PCR and single-strand conformation polymorphism is considered highly efficient and accurate for molecular diagnosis of CAH due to 21-hydroxylase deficiency.     

Structural analysis of the chimeric <Emphasis Type="Italic">CYP21P/CYP21</Emphasis> gene in steroid 21-hydroxylase deficiency

Congenital adrenal hyperplasia (CAH) is a common autosomal recessive disorder mainly caused by defects in the steroid 21-hydroxylase (CYP21) gene. More than 90% of CAH cases are caused by mutations of the CYP21 gene. Approximately 75% of the defective CYP21 genes are generated through intergenic recombination, termed “apparent gene conversion,” from the neighboring CYP21P pseudogene. A chimeric CYP21P/CYP21 gene with its 5′ end corresponding to CYP21P and 3′ end corresponding to CYP21 has been identified. This type of gene is nonfunctional because it produces a truncated protein. We found two distinct chimeric genes in CAH patients. Both genes had a sequence with −300 nucleotides of the 5′ head as the CYP21P gene. The coding region consisted of a fusion molecule with the CYP21P gene in two different regions. One of the junctions was located in the chi-like sequence of GCTGGGC in the third intron and the other was in the minisatellite consensus TGGCAGGAGG of exon 5 of the CYP21P gene. In addition, analysis of restriction fragment length polymorphism for these two 3.3-kb chimeric molecules showed that these sequences arose as a consequence of unequal crossover between the CYP21P and CYP21 genes. It is plausible that both consensus sequences are responsible for the gene conversion of these two chimeric genes. Received: March 13, 2002 / Accepted: June 17, 2002     

Functional studies of two novel and two rare mutations in the 21-hydroxylase gene

Congenital adrenal hyperplasia (CAH) is most commonly due to 21-hydroxylase deficiency and presents with a wide spectrum of clinical manifestations, from prenatal virilization and salt-wasting in the neonatal period to precocious pubarche and late-onset hyperandrogenic symptoms during adulthood. A limited number of mutations account for the majority of all mutated alleles, but a growing number of rare mutations are responsible for the disease in some patients. By sequence analysis of the CYP21A2 gene, we identified two novel (I171N and L446P) and two rare (R341P and R426H) mutations in seven Italian patients with CAH. One of the patients was diagnosed with mild non-classical CAH and was found to be a compound heterozygote (I171N/V281L), while all other patients showed severe phenotypes with latent or manifest salt-wasting. The residual activities measured after expression of the four mutant enzymes in COS-1 cells were all below 1% towards both natural substrates (17-OH-progesterone and progesterone) compared with the wild-type protein. All four mutations are, thus, associated with severe enzyme deficiency and are predicted to cause classic CAH if found in trans with other mutations causing severe enzyme deficiency.     

Structural analysis of the chimeric CYP21P/CYP21 gene in steroid 21-hydroxylase deficiency

Congenital adrenal hyperplasia (CAH) is a common autosomal recessive disorder mainly caused by defects in the steroid 21-hydroxylase (CYP21) gene. More than 90% of CAH cases are caused by mutations of the CYP21 gene. Approximately 75% of the defective CYP21 genes are generated through intergenic recombination, termed "apparent gene conversion," from the neighboring CYP21Ppseudogene. A chimeric CYP21P/CYP21gene with its 5' end corresponding to CYP21P and 3' end corresponding to CYP21 has been identified. This type of gene is nonfunctional because it produces a truncated protein. We found two distinct chimeric genes in CAH patients. Both genes had a sequence with -300 nucleotides of the 5' head as the CYP21P gene. The coding region consisted of a fusion molecule with the CYP21P gene in two different regions. One of the junctions was located in the chi-like sequence of GCTGGGC in the third intron and the other was in the minisatellite consensus TGGCAGGAGG of exon 5 of the CYP21P gene. In addition, analysis of restriction fragment length polymorphism for these two 3.3-kb chimeric molecules showed that these sequences arose as a consequence of unequal crossover between the CYP21Pand CYP21 genes. It is plausible that both consensus sequences are responsible for the gene conversion of these two chimeric genes.     

Identification of the recombination site within the steroid 21-hydroxylase gene (CYP21) of the HLA-B47,DR7 haplotype.

The HLA haplotype A3-Cw6-B47-C4A91-BQ0-DR7 is associated with congenital adrenal hyperplasia (CAH), since it only carries the dysfunctional steroid 21-hydroxylase A pseudogene as well as the 5' adjacent complement C4A gene. The recombination site leading to the deletion of the complement C4B and steroid 21-hydroxylase B genes in this haplotype was studied by determining the 21-hydroxylase genomic DNA sequence in comparison to the standard CYP21A- and CYP21B-specific sequences. A 200-bp region between exons 7 and 8 was identified as a possible recombination site. Thus the deleted area comprises the 3' end of the CYP21A pseudogene, the entire C4B gene and the 5' end of the CYP21B gene. The findings were confirmed by PCR amplification of a 1.8-kb fragment of the CYP21 gene. This PCR system is specific for CYP21A/B recombinant genes and may be used for screening among CAH patients carrying this type of deletion.     

Splicing mutation in CYP21 associated with delayed presentation of salt-wasting congenital adrenal hyperplasia

Patients with salt-wasting congenital adrenal hyperplasia (SW-CAH) most commonly carry an A-G transition at nucleotide 656 (nt 656 A→G), causing abnormal splicing of ex-ons 2 and 3 in CYP21, the gene encoding active steroid 21-hydroxylase. Affected infants are severely deficient in cortisol and aldo-sterone, and usually come to medical attention during the neonatal period. We report on 2 affected boys, homozygous for the nt 656 mutation, who thrived in early infancy, but suffered salt-wasting crises unusually late in infancy, at 3.5 and 5.5 months, respectively. Laboratory studies at presentation showed hyponatremia, hyperkalemia, dehydration, and acidosis; serum aldo-sterone was low in spite of markedly elevated plasma renin activity. Basal 17-hydroxyprogesterone levels were only moderately elevated, yet the stimulated levels were more typical of severe, classic CAH due to 21-hydroxylase deficiency. Genomic DNA from the patients was analyzed. Southern blot showed no major deletions or rearrangements. CYP21 -specific amplification by polymerase chain reaction, coupled with allele-specific hybridization using wild-type and mutant probes at each of 9 sites for recognized disease-causing mutations, revealed a single, homozygous mutation in each patient: nt 656 A→G. These results were confirmed by sequence analysis. We conclude that the common nt 656 A→G mutation is sometimes associated with delayed phenotypic expression of SW-CAH. We speculate that variable splicing of the mutant CYP21 may modify the clinical manifestations of this disease. © 1995 Wiley-Liss, Inc.     

Functional characterization of three CYP21A2 sequence variants (p.A265V,p.W302S,p.D322G) employing a yeast co‐expression system

Congenital adrenal hyperplasia (CAH) due to steroid 21‐hydroxylase (CYP21A2) deficiency is the commonest inborn error in steroid hormone biosynthesis. Functional in vitro assessment of mutant activity generally correlates well with clinical phenotype and therefore has contributed greatly to phenotype prediction in this CAH variant. Three CYP21A2 sequence variants (g.1641C>T, p.A265V; g.1752G>C, p.W302S; and g.2012A>G, p.D322G) identified in patients with non‐classic and simple virilizing CAH were characterized using a yeast co‐expression system and a computational three‐dimensional CYP21A2 model. Computational analysis of the mutants in the three‐dimensional structural model predicted no relevant effect of p.A265V, while p.W302S and p.D322G were predicted to impact significantly on enzyme function. Consistent with these findings, in vitro mutant analysis revealed enzyme activity similar to wild‐type for p.A265V, whereas p.W302S and p.D322G exerted activities compatible with simple virilizing and non‐classical CAH, respectively. The results indicate that p.A265V is an allelic variant rather than a disease‐causing amino acid change, whilst p.W302S and p.D322G could be confirmed as functionally relevant mutations. These findings emphasize the value of in vitro functional analysis of sequence variations in predicting genotype‐phenotype correlations and disease severity. © 2008 Wiley‐Liss, Inc.     

Highly polymorphic human CYP4A11 gene

The cytochrome P450 (CYP) is a monooxidase, which regulates metabolism of drugs and fatty acids in the liver and kidney. Among isoforms of the CYP4A subfamily, CYP4A11 is a major lauric acid (medium-length fatty acids) omega hydroxylase and is involved in the balance of lipids in the human liver. We performed direct DNA sequencing in 24 unrelated Korean individuals in the whole gene, including the 1-kb upstream region of CYP4A11. Seventy sequence variants were identified: six in exons, including two nonsynonymous SNPs; 60 in introns; and four in 3UTR. In comparison with SNPs enrolled in the SNP database (dbSNP) of the National Center for Biotechnology Inforfmation (NCBI), 26 novel polymorphisms (24 in introns and two in 3UTR) were identified in Korean subjects (n=24). The distributions of polymorphisms confirmed were significantly different from those in the dbSNP of the NCBI. Information clarified in this study would provide valuable for further studies, including genetic association studies for various diseases and drug responses.     

Ethnic-specific distribution of mutations in 716 patients with congenital adrenal hyperplasia owing to 21-hydroxylase deficiency

Congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency (21OHD) occurs worldwide. The most common mutations in the CYP21A2 gene in 716 unrelated patients were analyzed and the mutations were grouped by ethnicity, as defined through self-declaration corroborated by review of pedigrees extending to two or three generations. Prevalent allelic mutations and genotypes were found to vary significantly among ethnic groups, and the predominance of the prevalent mutations and genotypes in several of these populations was significant. There are ethnic-specific mutations in the CYP21A2 gene. A large deletion is prevalent in the Anglo-Saxons; a V281L (1685 G to T) mutation is prevalent in Ashkenazi Jews; an R356W (2109 G to A) mutation is prevalent in the Croatians; an IVS2 AS -13 (A/C to G) mutation is prevalent in the Iranians and Yupik-speaking Eskimos of Western Alaska; and a Q318X (1994 C to T) mutation is prevalent in East Indians. Genotype/phenotype non-correlation was seen when at least one IVS2 AS -13 (A/C to G) mutation in the CYP21A2 gene was present.     

CYP21A2 mutation update: Comprehensive analysis of databases and published genetic variants

Congenital adrenal hyperplasia (CAH) is a group of autosomal recessive disorders of adrenal steroidogenesis. Disorders in steroid 21‐hydroxylation account for over 95% of patients with CAH. Clinically, the 21‐hydroxylase deficiency has been classified in a broad spectrum of clinical forms, ranging from severe or classical, to mild late onset or non‐classical. Known allelic variants in the disease causing CYP21A2 gene are spread among different sources. Until recently, most variants reported have been identified in the clinical setting, which presumably bias described variants to pathogenic ones, as those found in the CYPAlleles database. Nevertheless, a large number of variants are being described in massive genome projects, many of which are found in dbSNP, but lack functional implications and/or their phenotypic effect. In this work, we gathered a total of 1,340 GVs in the CYP21A2 gene, from which 899 variants were unique and 230 have an effect on human health, and compiled all this information in an integrated database. We also connected CYP21A2 sequence information to phenotypic effects for all available mutations, including double mutants in cis. Data compiled in the present work could help physicians in the genetic counseling of families affected with 21‐hydroxylase deficiency.     

Chimeric CYP21A1P/CYP21A2 genes identified in Czech patients with congenital adrenal hyperplasia

Congenital adrenal hyperplasia (CAH) comprises a group of autosomal recessive disorders caused by an enzymatic deficiency which impairs the biosynthesis of cortisol and, in the majority of severe cases, also the biosynthesis of aldosterone. Approximately 95% of all CAH cases are caused by mutations in the steroid 21-hydroxylase gene (CYP21A2). The CYP21A2 gene and its inactive pseudogene (CYP21A1P) are located within the HLA class III region of the major histocompatibility complex (MHC) locus on chromosome 6p21.3. In this study, we describe chimeric CYP21A1P/CYP21A2 genes detected in our patients with 21-hydroxylase deficiency (21OHD). Chimeric CYP21A1P/CYP21A2 genes were present in 171 out of 508 mutated CYP21A2 alleles (33.8%). We detected four types of chimeric CYP21A1P/CYP21A2 genes: three of them have been described previously as CH-1, CH-3, CH-4, and one type is novel. The novel chimeric gene, termed CH-7, was detected in 21.4% of the mutant alleles. Possible causes of CYP21A1P/CYP21A2 formation are associated with 1) high recombination rate in the MHC locus, 2) high recombination rate between highly homologous genes and pseudogenes in the CYP21 gene area, and 3) the existence of chi-like sequences and repetitive minisatellite consensus sequences in CYP21A2 and CYP21A1P which play a role in promoting genetic recombination.     

Chimeric CYP21P/CYP21 and TNXA/TNXB genes in the RCCX module

Two types of chimeric RCCX modules found in chromosome 6p21.3 are the chimeras CYP21P/CYP21 and TNXA/TNXB. The CYP21P-specific sequence of chimera CYP21P/CYP21 has the 5'-end in common, but differs in the 3'-end of CYP21-specific genes. The sequence organization of the gene array is C4A-CYP21P/CYP21-TNXB, whereas chimera TNXA/TNXB is caused by a CYP21 deletion, and a partial TNXB replaced by the TNXA gene shows the C4A-CYP21P-TNXA/TNXB sequence. Therefore, chimeras CYP21P/CYP21 and TNXA/TNXB are two distinct hybrid genes produced in the RCCX module in HLA class III. In addition, the haplotype of CYP21 with chimera CYP21P/CYP21 causes 21-hydroxylase deficiency in congenital adrenal hyperplasia (CAH), while chimera TNXA/TNXB is associated with Ehlers-Danols syndrome as well as CAH.     

Use of TaqI digestion may lead to incorrect molecular diagnosis of congenital adrenal hyperplasia due to 21-hydroxylase deficiency

Congenital adrenal hyperplasia (CAH) is a common autosomal recessive disorder mainly caused by defects in the steroid 21-hydroxylase (CYP21) gene. For reliable and accurate mutation detection in the CYP21 gene it is important to separate the CYP21 gene from the highly homologous CYP21P pseudogene. For this, several different strategies have been developed. In the analysis of the common eight nucleotide deletion at codon 110-112, a strategy using the TaqI restriction enzyme was first applied. In one family, the results showed discordance between parents and offspring. The use of microsatellite markers flanking the genuine CYP21 gene did not lead to a correct assignment. The problem was finally resolved by using differential PCR amplification for generating a CYP21-specific template. It was concluded that incomplete TaqI digestion, although not visible on an agarose gel, allowed the amplification of the CYP21P pseudogene, thus leading to a false positive diagnosis. Therefore, we recommend the use of direct gene-specific primers for the essential step in the molecular diagnosis of congenital adrenal hyperplasia due to steroid 21-hydroxylase deficiency.     

Identification of non-amplifying CYP21 genes when using PCR-based diagnosis of 21-hydroxylase deficiency in congenital adrenal hyperplasia (CAH) affected pedigrees

Steroid 21-hydroxylase deficiency is among the most common inborn errors of metabolism in man. Characterization of mutations in the 21- hydroxylase gene (CYP21) has permitted genetic diagnosis, facilitated by the polymerase chain reaction (PCR). The most common mutation is conversion of an A or C at nt656 to a G in the second intron causing aberrant splicing of mRNA. Homozygosity for nt656G is associated with profoundly deficient adrenal cortisol and aldosterone synthesis, secondary hypersecretion of adrenal androgens, and a severe form of congenital adrenal hyperplasia (CAH) characterized by ambiguous genitalia and/or sodium wasting in newborns. During the course of genetic analysis of CYP21 mutations in CAH families, we and others have noticed a number of relatives genotyped as nt656G homozygotes, yet showing no clinical signs of disease. A number of lines of evidence have led us to propose that the putative asymptomatic nt656G/G individuals are incorrectly typed due to dropout of one haplotype during PCR amplification of CYP21. For prenatal diagnosis, we recommend that microsatellite typing be used as a supplement to CYP21 genotyping in order to resolve ambiguities at nt656.      

Molecular analysis of CYP21A2 can optimize the follow‐up of positive results in newborn screening for congenital adrenal hyperplasia

Neonatal screening for congenital adrenal hyperplasia (CAH) is useful in diagnosing salt wasting form (SW). However, there are difficulties in interpreting positive results in asymptomatic newborns. The main objective is to analyze genotyping as a confirmatory test in children with neonatal positive results. Patients comprised 23 CAH children and 19 asymptomatic infants with persistently elevated 17‐hydroxyprogesterone (17OHP) levels. CYP21A2 gene was sequenced and genotypes were grouped according to the enzymatic activity of the less severe allele: A1 null, A2 < 2%, B 3–7%, C > 20%. Twenty‐one children with neonatal symptoms and/or 17OHP levels > 80 ng/ml carried A genotypes, except two virilized girls (17OHP < 50 ng/ml) without CAH genotypes. Patients carrying SW genotypes (A1, A2) and low serum sodium levels presented with neonatal 17OHP > 200 ng/ml. Three asymptomatic boys carried simple virilizing genotypes (A2 and B): in two, the symptoms began at 18 months; another two asymptomatic boys had nonclassical genotypes (C). The remaining 14 patients did not present CAH genotypes, and their 17OHP levels were normalized by 14 months of age. Molecular analysis is useful as a confirmatory test of CAH, mainly in boys. It can predict clinical course, identify false‐positives and help distinguish between clinical forms of CAH.