Mari Satoh

New Compound Heterozygous Mutation in the CYP17 Gene in a 46,XY Girl with 17α-Hydroxylase/17,20-Lyase Deficiency

Background: 17α-Hydroxylase/17,20-lyase deficiency is caused by a defect of P450c17 which catalyzes both 17α-hydroxylase and 17,20-lyase reactions in adrenal glands and gonads. Results: In the present study, we analyzed the CYP17 gene in a Japanese patient with 17α-hydroxylase/17,20-lyase deficiency. The patient was a phenotypic girl and referred to us for right-sided inguinal hernia at the age of 4 years. Biopsy of the herniated gonad showed testicular tissue. The karyotype was 46,XY. At 6 years of age, hypertension was clearly recognized and the patient was diagnosed as having 17α-hydroxylase/17,20-lyase deficiency based on the clinical and laboratory findings. Analysis of the CYP17 gene revealed a compound heterozygous mutation. One mutation was an undescribed single nucleotide deletion at codon 247 in exon 4 (CTT to CT: 247delT) and the other was a missense mutation resulting in a substitution of His to Leu at codon 373 in exon 6 (CAC to CTC: H373L), which has been previously shown to abolish both 17α-hydroxylase and 17,20-lyase activities. The functional expression study of the 247delT mutant showed that this 247delT mutation completely eliminates both 17α-hydroxylase and 17,20-lyase activities. Conclusions: Together, these results indicate that the patient is a compound heterozygote for the mutation of the CYP17 gene (247delT and H373L) and that these mutations inactivate both 17α-hydroxylase and 17,20-lyase activities and give rise to clinically manifest 17α-hydroxylase/17,20-lyase deficiency.

GH and GnRH Analog Treatment in Children who Enter Puberty at Short Stature

It is well known that height at the onset of puberty is closely related to final height. To improve final height of short children who enter puberty at short stature, twenty-one short boys and six short girls were treated with a combination of GH and GnRH analog. The boys started the combination treatment at a mean age of 12.0 years when their mean height was 128.5 cm (-2.74 SD) and the girls at a mean age of 10.68 years when their mean height was 126.4 cm (-2.23 SD). The boys discontinued GnRH at a mean age of 16.88 years after a mean treatment period of 4.89 years when their height was 153.7 cm (-2.75 SD), and the girls at a mean age of 13.89 years after a mean treatment period of 3.20 years when their height was 143.3 cm (-1.94 SD). Bone age maturation significantly decelerated during the combination treatment. Bone age rarely exceeded 14 years in boys and did not exceed 13 years in girls. Bone age maturation during combination treatment decelerated after bone age 12 years in boys and 10.5 years in girls. On average, bone age matured at a mean rate of 0.48 years a year in boys and 0.56 years a year in girls during the combination treatment. During the combination treatment, height velocity did not decelerate rapidly and remained at 3-5 cm/year for a longer duration because of the bone age deceleration, although a definite pubertal growth spurt was not observed. As a consequence, the mean projected height SDS for bone age increased 1.50 (+/- 0.76) SD in boys and 1.24 (+/- 0.49) SD during the combination treatment. Although most of the patients have not yet reached their final height, combined GnRH analog and GH treatment should increase the pubertal height gain and the adult height in short children who enter puberty early for height, when the post-GST growth is taken into account. The combination treatment seems more effective in boys than in girls. This improvement is attributed to the lengthening of the treatment period by slower bone maturation and maintained growth velocity.

Two hyperandrogenic adolescent girls with congenital portosystemic shunt.

Abstract We describe two adolescent girls with a congenital portosystemic shunt who exhibited hyperandrogenism in addition to insulin resistant hyperinsulinaemia. Case 1 was referred to our clinic to undergo a routine clinical work-up prior to tonsillectomy at 14 years of age. Mild liver dysfunction was identified and hypogenesis of the portal vein with a congenital portosystemic shunt diagnosed. Primary amenorrhoea and virilization were evident and an endocrinological evaluation revealed hyperandrogenism and insulin resistant hyperinsulinaemia. Case 2 was referred at 15 years of age because of cardiomegaly. Mild liver dysfunction and hyperbilirubinaemia led to a diagnosis of agenesis of the portal vein with a congenital portosystemic shunt. Virilization was evident and an endocrinological evaluation revealed hyperandrogenism and insulin resistant hyperinsulinaemia. The haemodynamics of these patients were similar to those of secondary portosystemic shunt due to liver cirrhosis, which is often associated with hyperinsulinaemia and/or non-insulin dependent diabetes mellitus. On the other hand, hyperandrogenism is associated with certain insulin-resistant conditions with hyperinsulinaemia, including the polycystic ovary syndrome (PCO). Hyperinsulinaemia is believed to cause hyperandrogenism in patients with PCO by stimulating androgen production in both the ovary and adrenal gland. Therefore, in congenital portosystemic shunts, hyperinsulinaemia is also thought to cause hyperandrogenism due to the same mechanism. Conclusion A certain percentage of female patients with hyperandrogenism, likely including those with polycystic ovary syndrome may also have congenital portosystemic shunts. Our results indicate that serum levels of total bile acids and ammonia are prognostic indicators of this hepatic vascular anomaly.

Hypothyroidism caused by the combination of two heterozygous mutations: one in the TSH receptor gene the other in the DUOX2 gene

Abstract Subjects who are heterozygous for thyroid stimulating hormone receptor (TSHR) gene mutations present various phenotypes that range from euthyroid to hyperthyrotropinemia. Similarly, heterozygous dual oxidase 2 (DUOX2) gene mutations result in variable phenotypes, such as transient congenital hypothyroidism, subclinical hyperthyrotropinemia, and euthyroid in children. Here, we describe an 8-year-old boy who had normal newborn screening results, but who developed nonautoimmune hypothyroidism at the age of 1 year and 8 months of age. He was heterozygous for previously reported R450H-TSHR mutation and heterozygous for a novel double mutant allele A1323T-DUOX2 and L1343F-DUOX2. He needed levothyroxine (l-T4) replacement therapy to keep serum TSH levels within normal limits; l-T4 dose of 2.01–2.65 μg/kg/day corresponded to the dose taken by children homozygous for R450H-TSHR and by children with permanent congenital hypothyroidism. Therefore, the coexistence of a heterozygous TSHR mutation and a heterozygous DUOX2 mutation may have affected the severity of his hypothyroid condition.

Congenital hypothyroidism caused by a novel mutation of the dual oxidase 2 (DUOX2) gene

Abstract The dual oxidase 2 (DUOX2) mutation results in an impairment of the hydrogen peroxidase-generating system and is identified as a dyshormonogenic cause of congenital hypothyroidism (CH). Here, we describe two unrelated Japanese girls with CH due to a novel DUOX2 mutation. They had high serum thyrotropin levels and low free thyroxine/thyroxine concentrations during the neonatal period. A novel missense mutation with a transversion of G to A at position 1462 in exon 12 of the DUOX2 gene that caused a replacement of glycine (G) with arginine (R) at codon 488 of the protein (c.1462G>A, p.[G488R]) was identified. One patient was a compound heterozygote for p.[L479SfsX3]+[G488R]. The other was homozygous for p.[G488R]. This p.G488R substitution occurred in a highly conserved glycine residue of the mammalian DUOX2 protein. The two patients had different haplotypes, suggesting that the p.G488R alleles were the result of independent, recurrent mutations. Later in life, both patients were still euthyroid even after discontinuing thyroid hormone therapy. We conclude that this p.G488R missense mutation in the DUOX2 gene of the patients is associated with thyroid dysfunction that presents during the neonatal period.

Bone age: assessment methods and clinical applications.

Abstract. The main bone age assessment methods are the Greulich-Pyle and Tanner-Whitehouse 2 methods, both of which involve left hand and wrist radiographs. Several other bone age assessment methods have been developed, including ultrasonographic, computerized, and magnetic resonance (MR) imaging methods. The ultrasonographic method appears unreliable in children with delayed and advanced bone age. MR imaging is noninvasive; however, bone age assessment using MR imaging is relatively new, and further examinations are needed. An automated method for determining bone age, named BoneXpert, has been validated for Caucasian children with growth disorders and children of various ethnic groups. Sex hormones are necessary for bone growth and maturation in children with a bone age corresponding to normal pubertal age, and estrogen is essential for growth plate closure. Bone age is an effective indicator for diagnosing and treating various diseases. A new method for adult height prediction based on bone age has been developed using BoneXpert, in addition to the commonly used Bayley-Pinneau and Tanner-Whitehouse mark II methods. Furthermore, bone age may become a predictor for the timing of peak height velocity and menarche.

Analysis of Bone Age Maturation and Growth Velocity in Isolated Growth Hormone (GH) Deficient Boys with and without Gonadal Suppression Treatment and in GH Deficient Boys with Associated Gonadotropin Deficiency

Bone age maturation and growth velocity were analyzed longitudinally by the TW2 RUS method standardized for Japanese children in 45 GH-treated boys with idiopathic GH deficiency (GHD). The patients were divided into three groups: Group I consisted of four isolated GHD patients who underwent spontaneous puberty without gonadotropin suppression treatment (GST) and had a mean final height of 151.9 cm; Group II consisted of 24 GHD patients with associated gonadotropin deficiency who received sex hormone replacement treatment (GRT) and had a mean final height of 165.3 cm; Group III consisted of 17 isolated GHD patients who underwent spontaneous puberty and had a mean final height of 158.3 cm after being treated with combined GH and GST. Bone age matured along with chronological age in Group I, whereas bone age in Group II decelerated significantly after a bone age of 12 years and did not reach a bone age of 14 years. Bone age maturation in Group III showed an intermediate pattern between Groups I and II; bone age decelerated significantly after a bone age of 12 years but mean bone age advanced beyond a bone age of 14 years. Height velocity in Group I during GH treatment decelerated rapidly after the pubertal growth spurt, as usually seen in normal puberty. A definite pubertal growth spurt was not observed in the height velocity of Group II during GH treatment before receiving GRT; the mean height velocity gradually declined, remaining at 3.5-4.5 cm/year even after 18 years. Mean height velocity in Group III during GH treatment and GST showed a similar tendency as Group II, but it declined more rapidly. Since a growth velocity of around 3 cm/year was preserved with GH treatment despite the decline in growth velocity, the slower the advance of bone age, the longer the treatment period and, therefore, the taller the final height achieved by GST compared to Group I. It is recommended to start GST at a bone age between 11.5 years and 13 years. The timing, namely when to start GRT in GHD with gonadotropin deficiency or when to stop GST in isolated GHD, can be estimated according to the patients desired final height and bone age-growth potential.

Thyroid Dysfunction in Neonates Born to Mothers Who Have Undergone Hysterosalpingography Involving an Oil-Soluble Iodinated Contrast Medium

Background/Aims: Patients developing neonatal thyroid dysfunction following maternal hysterosalpingography (HSG) involving the use of oil-soluble iodinated contrast medium (ethiodized oil) have been reported. The present study aimed to investigate the frequency and risk factors for neonatal thyroid dysfunction following HSG. Methods: We studied 212 infants born to mothers who had become pregnant after undergoing HSG involving the use of ethiodized oil. Results: Five of the 212 infants tested positive during congenital hypothyroidism screening; this frequency (2.4%) was higher than the recall rate among first congenital hypothyroidism screening results (0.7%) in Tokyo, Japan. Two of the 5 screening-positive infants showed hypothyroidism, and 3 showed hyperthyrotropinemia. The urinary iodine concentrations in 4 out of the 5 screening-positive infants were 1,150, 940, 1,570, and 319 μg/l. The subjects were divided into thyroid dysfunction (n = 5) and normal thyroid function (n = 207) groups. The median dosage of ethiodized oil in the thyroid dysfunction group was significantly higher than in the normal thyroid function group (20 vs. 8 ml, p = 0.033). Conclusion: When infertile women undergo HSG, the dosage of oil-soluble iodinated contrast medium should be as low as possible to minimize the risk of fetal or neonatal thyroid dysfunction.

Genetic Analysis in Children with Transient Thyroid Dysfunction or Subclinical Hypothyroidism Detected on Neonatal Screening

About 30% of children with elevated TSH levels during neonatal screening have a transient form of disorder. On the other hand, it has been reported that subclinical hypothyroidism persists in late childhood in about 30% of children found to be false-positive during neonatal screening. The aim of this study was to determine whether transient thyroid dysfunction and subclinical hypothyroidism detected during neonatal screening are influenced by genetic background. The TSH receptor (TSHR), thyroid peroxidase (TPO) and dual oxidase 2 (DUOX2) genes, for which it has been reported that heterozygous defects cause neonatal transient thyroid dysfunction, were analyzed. Nine children with transient thyroid dysfunction or subclinical hypothyroidism detected during neonatal screening were studied. One child was heterozygous for a TSHR gene mutation (R450H), and another child was heterozygous for a TPO gene mutation (P883S). No children with mutation of the DUOX2 gene were identified. Genetic background may contribute to development of transient thyroid dysfunction and subclinical hypothyroidism detected during neonatal screening.

Anabolic Steroid and Gonadotropin Releasing Hormone Analog Combined Treatment Increased Pubertal Height Gain and Adult Height in Two Children who Entered Puberty with Short Stature

We studied the effect of gonadal suppression treatment in combination with anabolic steroid on pubertal height gain and adult height in two children who entered puberty with short stature. Patient 1 was a female with idiopathic short stature. She received combined treatment with an anabolic steroid (stanozolol) and a gonadotropin releasing hormone analog (leuprorelin acetate). Her pubertal height gain was 28.5 cm, which is greater than that in normal height girls (20-25 cm). Patient 2 was a male with Aarskog syndrome. Although his growth hormone (GH) secretion was normal, he received GH treatment. Since GH administration did not accelerate his growth, he received combined treatment with stanozolol and leuprorelin acetate. His pubertal height gain was 27.0 cm, which is greater than that observed in GH deficient boys treated with GH alone (21.9 cm). Combined treatment with stanozolol and leuprorelin acetate appears to be effective in increasing pubertal height gain and adult height in children who enter puberty with short stature.