Perinatal health services organization for preterm births: a multinational comparison.

OBJECTIVE: To explore population characteristics, organization of health services and comparability of available information for very low birth weight or very preterm neonates born before 32 weeks' gestation in 11 high-income countries contributing data to the International Network for Evaluating Outcomes of Neonates (iNeo). STUDY DESIGN: We obtained population characteristics from public domain sources, conducted a survey of organization of maternal and neonatal health services and evaluated the comparability of data contributed to the iNeo collaboration from Australia, Canada, Finland, Israel, Italy, Japan, New Zealand, Spain, Sweden, Switzerland and UK. RESULTS: All countries have nationally funded maternal/neonatal health care with >90% of women receiving prenatal care. Preterm birth rate, maternal age, and neonatal and infant mortality rates were relatively similar across countries. Most (50 to >95%) between-hospital transports of neonates born at non-tertiary units were conducted by designated transport teams; 72% (8/11 countries) had designated transfer and 63% (7/11 countries) mandate the presence of a physician. The capacity of 'step-down' units varied between countries, with capacity for respiratory care available in <10% to >75% of units. Heterogeneity in data collection processes for benchmarking and quality improvement activities were identified. CONCLUSIONS: Comparability of healthcare outcomes for very preterm low birth weight neonates between countries requires an evaluation of differences in population coverage, healthcare services and meta-data.

Effect of L-thyroxine supplementation on very low birth weight infants with transient hypothyroxinemia of prematurity at 3 years of age.

OBJECTIVE: To evaluate the effects of levothyroxine (L-T4) supplementation on growth and neurodevelopmental outcomes at 3 years of age in very low birth weight (VLBW) infants with transient hypothyroxinemia of prematurity (THOP). STUDY DESIGN: VLBW infants with plasma thyroid-stimulating hormone concentrations <10 mIU l-1 and free thyroxine concentrations <0.8 ng dl-1 were defined as having THOP and randomly assigned to the Treated (20 infants) or Untreated (31 infants) group. The Treated group received L-T4 at a dose of 5 µg kg-1 day-1. Growth and neurodevelopmental outcomes at 3 years of age were compared between the two groups. RESULTS: There were no significant differences in body length, body weight or head circumference mean s.d. scores or in neurodevelopmental outcomes between the two groups. CONCLUSION: L-T4 supplementation in VLBW infants with THOP demonstrated no beneficial effect at 3 years of age.

Hypertensive disorders of pregnancy and outcomes of preterm infants of 24 to 28 weeks' gestation.

OBJECTIVE: To examine the relationship between hypertensive disorders of pregnancy (HDPs) and mortality and major morbidities in preterm neonates born at 24 to 28 weeks of gestation. STUDY DESIGN: Using an international cohort, we retrospectively studied 27 846 preterm neonates born at 240 to 286 weeks of gestation during 2007 to 2010 from 6 national neonatal databases. The incidence of HDP was compared across countries, and multivariable logistic regression analyses were conducted to examine the association of HDP and neonatal outcomes including mortality to discharge, bronchopulmonary dysplasia, severe brain injury, necrotizing enterocolitis and treated retinopathy of prematurity. RESULTS: The incidence of HDP in the entire cohort was 13% (range 11 to 16% across countries). HDP was associated with reduced odds of mortality (adjusted odds ratio (aOR) 0.77; 95% confidence interval (CI) 0.67 to 0.88), severe brain injury (aOR 0.74; 95% CI 0.62 to 0.89) and treated retinopathy (aOR 0.82; 95% CI 0.70 to 0.96), but increased odds of bronchopulmonary dysplasia (aOR 1.16; 95% CI 1.05 to 1.27). CONCLUSIONS: In comparison with neonates born to mothers without HDP, neonates of HDP mothers had lower odds of mortality, severe brain injury and treated retinopathy, but higher odds of bronchopulmonary dysplasia. The impact of maternal HDP on newborn outcomes was inconsistent across outcomes and among countries; therefore, further international collaboration to standardize terminology, case definition and data capture is warranted.

Impact of pulmonary hypertension on neurodevelopmental outcome in preterm infants with bronchopulmonary dysplasia: a cohort study.

OBJECTIVES: To evaluate the impact of pulmonary hypertension (PH) on long-term growth and neurodevelopmental outcomes of extremely preterm infants with bronchopulmonary dysplasia (BPD). STUDY DESIGN: A single-center retrospective cohort of preterm infants born at <28 weeks gestational age from 2000 to 2011 was evaluated at 3 years of age. Growth and neurodevelopmental outcomes were compared among 3 groups: non-BPD, BPD without PH and BPD with PH. BPD was defined according to oxygen demand at 36 weeks postmenstrual age. PH was diagnosed by echocardiography during the neonatal intensive care unit stay. RESULTS: Sixty-two infants without BPD, 60 with BPD without PH and 20 with BPD with PH were analyzed. Regardless of PH status, somatic growth was smaller in both BPD groups of infants than in non-BPD infants, with further reduction in the group having BPD with PH. Furthermore, a developmental quotient of <70 was more prevalent in the BPD infants with PH than in the BPD infants without PH (odds ratio (OR): 4.37; 95% confidence interval, CI: 1.16 to 16.5). Multivariate analysis demonstrated that BPD with PH was one of the independent perinatal risk factors for developmental quotient <70 at 3 years of age (OR: 4.94, 95% confidence interval: 1.06 to 24.1). CONCLUSION: PH had an additional negative effect on long-term growth and neurodevelopmental outcomes of extremely preterm infants with BPD.

Outcomes of peripherally inserted double lumen central catheter in very low birth weight infants.

OBJECTIVE: In order to evaluate safety and usefulness of peripherally inserted double lumen central catheter (PIDLCC) in very low birth weight (VLBW) infants, outcomes of VLBW infants who had PIDLCC was studied. SUBJECTIVE: Thirty-nine VLBW infants who were admitted to our NICU in 2013 were retrospectively analyzed. RESULTS: Mean birth weight and gestational age was 1042.7 gram and 28.5 weeks, respectively. Total duration of indwelling PIDLCC was 1121 days (mean 28.5+18.2 days) with 85 PIDLCCs used. Dressing at the insertion site was done twice weekly with 10% povidone iodine. Four (10.3% with mean of 48 days) infants had catheter-related blood stream infection (CRBSI), with a 3.57 infection per 1000 catheter-day. The mean for days of PIDLCC in 35 infants without CRBSI was 26.5 days. Organisms isolated were Staphylococcus epidermidis, Staphylococcus aureus and Staphylococcus capitis ureolytic. Our study showed significant difference in the duration of indwelling catheter (p = 0.023) and intraventricular hemorrhage (p = 0.043) between the CRBSI group and non-CRBSI group. Five (12.8%) infants had abnormal thyroid function test, in which two infants required thyroxine supplementation upon discharge. However, duration of PIDLCC and abnormal thyroid function test was not statistically significant (p = 0.218). One (2.5%) infant died (death was not related to CRBSI). There was no serious adverse effects secondary to PIDLCC. CONCLUSION: It is concluded that the use and maintenance of PIDLCC is safe for VLBW infants, but close monitoring should be observed to detect early signs of infection.

Fecal steroid metabolites and reproductive monitoring in a female Tsushima leopard cat (Prionailurus bengalensis euptilurus).

Although the Tsushima leopard cat (Prionailurus bengalensis euptilurus) is one of the most endangered mammals in Japan, its reproductive physiology and endocrinology have been not elucidated. The objective was to establish the non-invasive monitoring of reproductive endocrinology in a female Tsushima leopard cat and to identify the types of fecal reproductive steroid metabolites in this species. Fecal concentrations of estrogen and progestin were determined by enzyme immunoassays, from 60 d before to 60 d after the last copulation, during three pregnancies. Fecal estrogen metabolite concentrations were increased before/around the mating period and after mid-pregnancy. Fecal progestin metabolite concentrations increased after the last copulation and remained high during pregnancy. The gestation period was 65.0 ± 0.6 d (mean ± SD). Fecal extracts were separated by high-performance liquid chromatography for identification of fecal metabolites. Fecal estrogens were identified as estradiol-17ß and estrone. Fecal progestins during pregnancy contained 5α-reduced pregnanes: 5α-pregnan-3α-ol-20-one, 5α-pregnan-3ß-ol-20-one and 5α-pregnan-3,20-dione, and nonmetabolized progesterone was barely detected in feces. In conclusion, measurement of fecal estrogen and progestin metabolites was effective for noninvasive reproductive monitoring in the Tsushima leopard cat. An immunoassay for fecal estradiol-17ß concentrations seemed useful to monitor follicular activity, whereas an immunoassay with high cross reactivity for 5α-reduced pregnanes was useful to monitor ovarian luteal activity and pregnancy.

Clinical characterization and long-term prognosis of neurological development in preterm infants with late-onset circulatory collapse.

OBJECTIVE: To characterize the risk factors for late-onset circulatory collapse (LCC) in preterm infants responsive to corticosteroid therapy and evaluate the long-term neurological prognosis. STUDY DESIGN: A retrospective case-control study for preterm infants (≤32 weeks' gestation) admitted to our neonatal intensive care unit from 1994 through 2002. RESULT: Sixty-five infants (11%) were diagnosed with LCC. Infants with a shorter gestation and lower birth weight had a higher incidence of LCC. LCC infants had a significantly lower 1-min Apgar score, significantly higher incidence of severe intraventricular hemorrhage, chronic lung disease, and postnatal periventricular leukomalacia, and significantly longer duration of ventilation use, oxygen use, and hospital stay. Somatic growth at 36 weeks' postmenstrual age was poorer in infants with LCC than without LCC (controls). LCC infants were significantly more likely than controls to have cerebral palsy at 3 years. CONCLUSION: LCC is associated with poor neurodevelopmental outcomes. Prevention of LCC can lead to improved neurological prognoses.

Rapid normalization of marked dilatation of the cerebral duro-venous system in a newborn infant mimicking a great vein of Galen varix.

A newborn infant with a marked dilatation of the cerebral duro-venous system is presented. The patient was diagnosed as having a vein of Galen aneurysmal varix by a cranial ultrasound examination immediately following delivery. Computed tomographic angiography on the following day, however, showed a marked dilatation of the cerebral duro-venous system, including the great vein of Galen, superior sagittal sinus, torcular herophili and transverse sinuses. There were no arteriovenous fistulas at the vein of Galen. Dilatation of the duro-venous system and concomitant heart failure subsided rapidly after intravenous administration of indomethacin for the treatment of the patent ductus arteriosus on the fourth day of life. Dilatation of the duro-venous system in a newborn infant should be differentiated from any form of vein of Galen aneurysm.

[Seizures associated with fever in children of congenital adrenal hyperplasia].

We investigated seizures in 22 children with congenital adrenal hyperplasia (CAH), eight of whom had seizures associated with fever. The follow-up period was 5-18 years. The onset of seizures ranged from 1 to 4 years of age, and the total number of seizures was one to three in all cases. Four cases had seizures twice within 24 hours. None had seizures after 5 years of age. In two of the eight cases, the seizures may have caused by hypoglycemia or hyponatremia, in the remaining six they were considered to be febrile seizures. Three of them had first-degree relatives with febrile seizures. Electroencephalogram was recorded in five cases, with normal results in all of them. One case with febrile status developed localization-related epilepsy later. None showed developmental delay during follow-up. Although seizures in CAH have been ascribed to hypoglycemia and/or metabolic disorders (hyponatremia), our findings implicate unknown factors in the pathogenesis such as excess secretion of corticotropin releasing factor (CRF) under stress, prolonged elevation of CRF during fetus life and linkage between CAH and febrile seizures on the chromosome 6.

A prospective clinical study on inhaled nitric oxide therapy for neonates in Japan.

BACKGROUND: This is the first report about a prospective clinical investigation to study the efficacy and safety of nitric oxide (NO) inhalation in infants with persistent pulmonary hypertension of the newborn (PPHN) in Japan. METHODS: Patients in the present study had to meet the following entry criteria: (i) they had to be younger than 7 days of age; (ii) they had to have evidence of PPHN as defined by echocardiograph; (iii) they had to have severe systemic hypoxemia under mechanical ventilation at 100% oxygen supplementation; and (iv) they had to have a failure to respond to conventional therapies. Patients were excluded from this trial if they had any of the following: hypoplastic lung, structural cardiac lesions or severe multiple anomalies. RESULTS: Nitric oxide inhalation therapy was performed in 68 infants who had severe PPHN at 18 hospitals between May 1995 and May 1997. At birth, 21 of 68 infants (31%) weighed less than 1,500 g and 39 infants weighed more than 2,500 g. The diagnoses associated with PPHN were as follows: 27 infants had meconium aspiration syndrome, 15 infants had dry lung syndrome, nine infants had congenital diaphragmatic hernia, six infants had respiratory distress syndrome, three infants had pneumonia and eight infants had other diagnoses. The mean oxygenation index (OI) before NO inhalation therapy in 68 infants was 43.2; 55 infants (81%) had good responses. CONCLUSIONS: These results may be valuable for further randomized controlled and double-blind trials in Japan to evaluate whether NO inhalation therapy is more effective than conventional therapy in infants with severe PPHN.

Cerebral hemodynamics after exogenous surfactant administration for respiratory distress syndrome in piglet model.

OBJECTIVE: The rapid improvement of lung function after exogenous surfactant treatment for respiratory distress syndrome (RDS) can affect the functions of several other systems, which includes cerebral blood flow volume (CBF). To evaluate the change in CBF after treatment with exogenous surfactant, we measured CBF in a newborn piglet model with RDS. METHOD: After the lung lavage with normal saline, ten animals under mechanical ventilation were administered either 120 mg/kg surfactant-TA (Surfacten) or air placebo. Heart rate, blood pressure, dynamic lung compliance (Cdyn), PaO2, PaCO2, and CBF were recorded before and every 15 min after surfactant treatment up to 120 min. RESULTS: Cdyn was improved significantly at 45 min and later after treatment; that of the control group remained unchanged. PaO2 increased and PaCO2 decreased significantly after surfactant treatment in both groups. However, the improvement was significantly less in the control group. CBF significantly decreased by about 30% in the control group, and by about 50% in the treated group at 120 min, with a significant difference between groups. Almost 70% of the changes in CBF were attributable to changes in PaCO2 by multivariate regression analysis. CONCLUSIONS: Treatment with exogenous surfactant improves lung compliance, and has little effect on CBF itself. The drop in levels of PaCO2 after treatment, however, had a strong relationship with decreases in CBF.

Postnatal change of renal artery blood flow velocity and its relationship with urine volume in very low birth weight infants during the first month of life.

Although the renal artery blood flow velocity has been investigated recently using the ultrasound Doppler method, little is known about the longitudinal change of renal artery blood flow velocity and its relationship with urine volume in very low birth weight infant. Thus, we measured renal artery blood flow velocities by means of the pulse Doppler method in 28 very low birth weight infants. Maximum, minimum, and mean blood flow velocities were determined at postnatal days 0, 1, 2, 3, 4, 5, 6, 13, 20, and 27. The resistance index was also calculated. The maximum and mean blood flow velocities increased gradually after birth, and were significantly higher at 13, 20, and 27 days after birth. The minimum blood flow velocity and the resistance index were relatively constant during the study period. The mean blood flow velocities were also analyzed for any correlation with urine volume. There was a poor correlation between urine volume (ml/kg/day) and mean blood flow velocity (cm/s) (Y = 2.38X + 57.4, Y: urine volume, X: mean blood flow velocity, n = 161, r = 0.338, P < 0.01). However, if the mean renal artery blood flow velocity was less than 10 cm/s, oliguria was observed in most cases. The measurement of the renal artery blood flow velocities appears to be useful in understanding the background condition of renal function in very low birth weight infants.

Cerebral blood flow during treatment for pulmonary hypertension.

AIM: To determine if the haemodynamics of systemic and cerebral circulation are changed during treatment for persistent pulmonary hypertension of the newborn (PPHN). METHODS: Fifteen term newborn piglets with hypoxia induced pulmonary hypertension were randomly assigned either tolazoline infusion (Tz), hyperventilation alkalosis(HAT), and inhaled nitric oxide (iNO). Mean pulmonary arterial pressure (PAP), mean systemic arterial pressure (SAP), and cerebral blood flow volume (CBF) were measured. RESULTS: During hypoxic breathing, PAP increased significantly in all groups. After treatment PAP decreased significantly in all groups, but no significant difference was observed between groups. SAP decreased significantly only in the Tz group, and CBF reduced significantly only in the HAT group. On the other hand, iNO did not change SAP or CBF. CONCLUSION: Inhaled NO might be ideal for the resolution of pulmonary hypertension.

Transumbilical embolization of a congenital dural arteriovenous fistula at the torcular herophili in a neonate. Case report.

A neonate, in whom a congenital cerebral vascular anomaly had been diagnosed prenatally, exhibited progressive high-output congestive heart failure soon after birth. Cerebral angiography revealed a congenital dural arteriovenous fistula (AVF) with a huge dural lake located at the torcular herophili. In addition to the meningeal blood supply, an unusual pial blood supply from all cerebellar arteries was observed to feed the fistula. The patient was treated by repeated transarterial and transvenous embolization through the umbilical venous route. To the authors' knowledge, neither the existence of a congenital dural AVF at the torcular herophili presenting with an enormous pial blood supply or the technique of trans-umbilical venous intervention has been reported in the literature.

16-Dehydropregnenolone 3-sulfate, its source and metabolism in the feto-placental unit.

We have investigated the serum concentration of 16-dehydropregnenolone (3 beta-hydroxy-5,16-pregnadien-20-one) 3-sulfate (16-DHPS) in the umbilical artery (U.A.), umbilical vein (U.V.) and maternal vein (M.V.) to discover the origin of 16-DHPS. Although there was no significant difference between the levels of 16-DHPS in U.A. (18 +/- 15 ng/ml, mean +/- SD., n = 28) and U.V. (10 +/- 9 ng/ml, n = 28), these values were significantly higher (U.A., p < 0.001; U.V., p < 0.001) than that in M.V. (2 +/- 3 ng/ml, n = 28). These levels in the U.A. and U.V. did not fall in infants (30 +/- 18 ng/ml, n = 7) during the early neonatal period (2-7 d after birth). A significant correlation between the serum levels of 16-DHPS and 16-hydroxypregnenolone (3 beta, 16 alpha-dihydroxy-5-pregnen-20-one) 3-sulfate (16-OH-PregS), which may be the precursor steroid for 16-DHPS, was observed in the U.A. (r = 0.630, n = 28, p < 0.001), but not in the U.V. Moreover, this significant correlation persisted during the early neonatal period (p < 0.05, r = 0.842, n = 7), although the neonate had been separated from the maternal milieu. These results suggest that 16-DHPS originates in the fetus. To confirm the metabolic pathway of 16-DHPS (i.e. pregnenolone (3 beta-hydroxy-5-pregnen-20-one) 3-sulfate (PregS)-->16-OH-PregS-->16-DHPS), we investigated the correlation between the serum concentrations of the precursor steroid and the product in both the U.A. and U.V. A significant correlation was obtained between the serum concentrations of PregS and 16-OH-PregS both in the U.A. (p < 0.001, r = 0.563, n = 28) and U.V. (p < 0.05, r = 0.476, n = 27). As described above, the serum levels of 16-DHPS and 16-OH-PregS only correlated significantly in the U.A. These findings support the existence of the pathway, PregS-->16-OH-PregS-->16-DHPS, in the fetus.

Localization of sphingomyelinase in lesional skin of atopic dermatitis patients.

Because it has been suggested that the majority of the activity hydrolysing [N-methyl-14C] sphingomyelin is due to sphingomyelin acylase in the lesional skins of atopic dermatitis (AD), in this study we used immunologic techniques to localize and quantitate sphingomyelinase in AD lesional and normal skin. A polyclonal antibody raised against a synthetic polypeptide corresponding to a portion of the amino acid sequence deduced from the cDNA of human acid sphingomyelinase, cross-reacted with a 58 kDa, pI 5.8 human epidermal protein in an immunoblot analysis. The 58 kDa protein-rich fraction, partially purified by immunoprecipitation, converted [N-methyl-14C]-sphingomyelin to 14C-phosphorylcholine and ceramides. The reaction products were immunohistochemically observed in the intercellular domain from the upper spinous cell layer to the upper stratum corneum cell layers in the lesional skin of AD patients. Immunoelectron-microscopically, gold particles appeared to be concentrated in the intercellular domains of the granular-upper stratum corneum cells in the lesional skin of AD patients. The total amount of the 58 kDa protein in a 7 mm2 area of the skin was measured by quantitative immunoblot analysis; and was slightly increased in the lesional skin samples [3.5 +/- 0.3 microg per 7 mm2 (n = 7)], as compared with the nonlesional skin samples of AD patients [2.8 +/- 0.19 microg per 7 mm2 (n = 10)] and with the normal skin samples [2.7 +/- 0.22 microg per 7 mm2 (n = 10)]. This difference (between the lesional skin of AD and the nonlesional skin of AD or the normal control) was significant (nonpaired student's t test, p < 0.05).

[Home mechanical ventilation with nasal intermittent positive pressure ventilation for a boy with congenital central hypoventilation syndrome].

We report a 4-year-old boy with congenital central hypoventilation syndrome (CCHS) successfully treated with home mechanical ventilation with nasal intermittent positive pressure ventilation (NIPPV) during sleep hours. He had had frequent severe apneic attacks from the neonatal period. At 8 months, he was treated with positive pressure ventilation following a tracheostomy. At 4 year and 2 months, NIPPV was attempted because of recurrent respiratory tract infections and cor pulmonale. The tracheostomy was successfully abandoned 6 months later. Adequate ventilation has been maintained for more than 3 years without troubles. NIPPV is an effective and non-invasive treatment of CCHS that it significantly improves the quality of life during daytime.

Three novel mutations and a de novo deletion mutation of the DAX-1 gene in patients with X-linked adrenal hypoplasia congenita.

The DAX-1 [DSS (dosage sensitive sex)-AHC critical region on the X, gene 1] gene is responsible for X-linked adrenal hypoplasia congenita (AHC). However, DAX-1 protein structure-function relationships are not well understood. Identification of missense mutations may help to reveal these relationships. We analyzed the DAX-1 gene from seven patients in six kindreds with X-linked AHC and identified one frameshift mutation, two missense mutations, and three deletion mutations. Case 1 had a 388delAG frameshift mutation, inducing a premature stop codon at position 70. Case 2 had a missense mutation, Lys382Asn, which encodes an asparagine (Asn) for lysine (Lys) at position 382. Sibling cases of 3-1 and 3-2 had a missense mutation of Trp291 Cys, which encodes a substitution of cysteine (Cys) for tryptophan (Try) at position 291. The tryptophan (Trp) at position 291 and lysine (Lys) at position 382 in human DAX-1 protein are highly conserved among other related orphan nuclear receptor superfamily members. Cases 4, 5, and 6 showed deletion mutation. In case 6, a de novo deletion mutation was revealed by both southern hybridization and polymerase chain reaction (PCR) of a GGAA tetranucleotide tandem repeat. These findings suggest that: 1) Trp at position 291 and Lys at position 382, located in the C-terminal presumptive ligand binding domain, are important to the functional role of the DAX-1 protein in adrenal embryogenesis and/or in hypothalamic-pituitary activity; and 2) molecular analysis of the DAX-1 gene may help genetic counseling, even in cases with deletion mutation, because a detection of de novo deletion may exclude another affected or carrier child.

Decreased level of prosaposin in atopic skin.

In the skin of atopic dermatitis patients, the amount of ceramides in the stratum corneum is decreased. Although the cause of this decrease may be due to the higher activity of acylase, a decrease in the activity of sphingolipid activator proteins may also be the cause. A polyclonal antibody to saposin D, elicited by immunizing rabbits with the synthetic polypeptide from cDNA of saposin D, cross-reacted with a single 65-kDa epidermal protein of pI 5.6 in a 2-dimensional immunoblot study, suggesting that it was prosaposin, the precursor protein of saposin D, from its molecular weight and demonstrating its immunohistochemical localization in the innermost cell layers of the stratum corneum of the skin. The antigenic material was also observed in the epithelium of the esophagus, pneumocytes of the lungs, hepatocytes, and glandular cells of the stomach. Immunoelectron microscopy showed the antigenic material in the cytoplasm of the granular cells and the intercellular spaces, either between the stratum granulosum and the stratum corneum or on the stratum corneum cell envelope. By ELISA, the amount of the 65-kDa protein in the inner surface skin of the upper arm of atopic dermatitis patients (nonlesional skin) [4.1 +/- 2.0 microg per 7 mm2 (mean +/- SD), n = 10] was found to be significantly decreased (p < 0.05) to 66% of that in the normal control (6.2 +/- 1.5 microg per 7 mm2, n = 10). Therefore, the suppression of prosaposin synthesis may be related to the abnormal stratum corneum formation in atopic skin through lower activation of glucosylcerebrosidase or sphingomyelinase.

Molecular basis of nonclassical steroid 21-hydroxylase deficiency detected by neonatal mass screening in Japan.

Since 1989, neonatal mass screening for congenital adrenal hyperplasia (CAH) has been performed in Japan, and the frequency of the classical form of 21-hydroxylase deficiency was found to be nearly identical to that in other countries. However, it has not yet been determined whether our mass screening program can detect the nonclassical (NC) form. From 1991 to 1994, about 4,500,000 infants underwent CAH mass screening in Japan. During this period, we identified by screening 2 siblings and 2 unrelated patients who had mild elevation of serum 17-hydroxyprogesterone levels at 5 days of age, but who revealed no symptoms of CAH. They were diagnosed as having probable NC steroid 21-hydroxylase deficiency. To clarify the molecular basis of NC CAH detectable by neonatal screening in Japan, the steroid 21-hydroxylase (CYP21) genes from these cases were analyzed. The 2 siblings (patients 1 and 2) had I172N and R356W mutations in 1 allele and in the other allele had local gene conversion, including the P30L mutation in exon 1. Patient 3, who was unrelated, had gene conversion encoding the same P30L mutation in 1 allele and in the other allele had an intron 2 mutation (668-12 A-->G), causing aberrant ribonucleic acid splicing, and the R356W mutation. Patient 4, also a compound heterozygote, had the R356W and 707del8 mutations. The estimated rate of detection of the NC form by mass screening (1:1,100,000) seemed low compare to the established detection rate for the classical form (1:18,000). As all of our 4 patients were compound heterozygotes with at least 1 allele bearing 1 or more mutations associated with classic CAH, it may be difficult to detect NC cases carrying only NC-associated alleles using our current neonatal mass screening methods.