Primrose syndrome: Characterization of the phenotype in 42 patients

Primrose syndrome (PS; MIM# 259050) is characterized by intellectual disability (ID), macrocephaly, unusual facial features (frontal bossing, deeply set eyes, down‐slanting palpebral fissures), calcified external ears, sparse body hair and distal muscle wasting. The syndrome is caused by de novo heterozygous missense variants in ZBTB20. Most of the 29 published patients are adults as characteristics appear more recognizable with age. We present 13 hitherto unpublished individuals and summarize the clinical and molecular findings in all 42 patients. Several signs and symptoms of PS develop during childhood, but the cardinal features, such as calcification of the external ears, cystic bone lesions, muscle wasting, and contractures typically develop between 10 and 16 years of age. Biochemically, anemia and increased alpha‐fetoprotein levels are often present. Two adult males with PS developed a testicular tumor. Although PS should be regarded as a progressive entity, there are no indications that cognition becomes more impaired with age. No obvious genotype‐phenotype correlation is present. A subgroup of patients with ZBTB20 variants may be associated with mild, nonspecific ID. Metabolic investigations suggest a disturbed mitochondrial fatty acid oxidation. We suggest a regular surveillance in all adult males with PS until it is clear whether or not there is a truly elevated risk of testicular cancer.

SENS-U: continuous home monitoring of natural nocturnal bladder filling in children with nocturnal enuresis - a feasibility study

INTRODUCTION

Enuresis is a common problem in children. One treatment option is a wetting alarm that provides an alarm when incontinence occurs. A drawback of this approach is that the child is still awakened by wet sheets. Recently, a wearable, wireless ultrasonic bladder sensor became available, the SENS-U, which has the potential to prevent the enuretic event by waking up the child before the bladder is full. In this first feasibility study, the aim is to perform a night-time, home-based evaluation of the SENS-U in children with monosymptomatic nocturnal enuresis (MNE).

PATIENTS AND METHODS

In this study, children (6-12 years) with MNE were included for a one-night monitoring session. During the night, the SENS-U continuously (i.e. every 30 s) estimated the filling status [notifications were deactivated]. In addition, urine volume was collected in a measurement cup (or diaper weight). The total measured natural nocturnal bladder filling (NNBF) cycles was analyzed by descriptive statistics. Before and after the measurement, sleep behavior was assessed by a selection of the Children's Sleep Habits Questionnaire.

RESULTS

Fifteen patients (boys/girls: 13/2) [mean age: 8.6 ± 1.5 years] have been enrolled. One patient was excluded due to inadequate sensor-to-skin contact. For 14 children, 18 NNBF cycles were recorded (voiding diary) of which three patients (21%) had more than one NNBF cycle. The SENS-U was able to successfully detect 83% of the NNBF cycles. The three missed NNBF cycles had a voided volume ≤30 ml, which was at the lower limit of the sensor's detection range. The SENS-U had no effect on sleeping behavior.

CONCLUSION

The SENS-U was able to monitor the natural nocturnal bladder filling successfully in children with monosymptomatic nocturnal enuresis at home, without disturbing their sleep. Future research focuses on investigating the usability of the SENS-U for both diagnostic - and treatment purposes.

Carboxyhemoglobin in umbilical cord blood and maternal smoking

Background Smoking during pregnancy still exists in daily life but the effect on the newborn in the early stage of life is still unclear. This study investigates the normal reference range of carboxyhemoglobin (HbCO) in umbilical cord blood gas (UBG). Methods A single center retrospective cross-sectional cohort study was performed with 1172 cases. We analyzed HbCO values in umbilical cord blood, maternal smoking, birth weight percentiles, duration of amenorrhea and maternal admission duration prior to delivery. Results HbCO levels in newborns range from 0 to 7.7% with a mean of 0.6% (standard deviation 0.6). Newborns from women who smoked during pregnancy have a significant higher HbCO value compared to newborns from women who did not smoke. Birth weight is negatively correlated with HbCO (P = 0.001). Conclusion Our results show the normal reference range in this study is 0-1.2% for HbCO in the umbilical blood of newborns. Smoking prior to delivery leads to a higher HbCO value in the UBG sample of the newborn, a lower birth weight and may be potential harmful.

Prevalence of growth hormone (GH) deficiency in previously GH-treated young adults with Prader-Willi syndrome

OBJECTIVE

Some features of subjects with Prader-Willi syndrome (PWS) resemble those seen in growth hormone deficiency (GHD). Children with PWS are treated with growth hormone (GH), which has substantially changed their phenotype. Currently, young adults with PWS must discontinue GH after attainment of adult height when they do not fulfil the criteria of adult GHD. Limited information is available about the prevalence of GHD in adults with PWS. This study aimed to investigate the GH/insulin-like growth factor (IGF-I) axis and the prevalence of GHD in previously GH-treated young adults with PWS.

DESIGN

Cross-sectional study in 60 young adults with PWS.

MEASUREMENTS

Serum IGF-I and IGFBP-3 levels, GH peak during combined growth hormone-releasing hormone (GHRH)-arginine stimulation test.

RESULTS

Serum IGF-I was <-2 standard deviation scores (SDS) in 2 (3%) patients, and IGFBP-3 was within the normal range in all but one patient. Median (IQR) GH peak was 17.8 μg/L (12.2; 29.7) [~53.4 mU/L] and below 9 μg/L in 9 (15%) patients. Not one patient fulfilled the criteria for adult GHD (GH peak < 9 μg/L and IGF-I < -2 SDS), also when BMI-dependent criteria were used. A higher BMI and a higher fat mass percentage were significantly associated with a lower GH peak. There was no significant difference in GH peak between patients with a deletion or a maternal uniparental disomy (mUPD).

CONCLUSIONS

In a large group of previously GH-treated young adults with PWS, approximately 1 in 7 exhibited a GH peak <9 μg/L during a GHRH-arginine test. However, none of the patients fulfilled the consensus criteria for adult GHD.

Bone mineral density in children and adolescents with Prader-Willi syndrome: a longitudinal study during puberty and 9 years of growth hormone treatment

CONTEXT

Longitudinal data on bone mineral density (BMD) in children and adolescents with Prader-Willi Syndrome (PWS) during long-term GH treatment are not available.

OBJECTIVE

This study aimed to determine effects of long-term GH treatment and puberty on BMD of total body (BMDTB), lumbar spine (BMDLS), and bone mineral apparent density of the lumbar spine (BMADLS) in children with PWS.

DESIGN AND SETTING

This was a prospective longitudinal study of a Dutch PWS cohort.

PARTICIPANTS

Seventy-seven children with PWS who remained prepubertal during GH treatment for 4 years and 64 children with PWS who received GH treatment for 9 years participated in the study.

INTERVENTION

The children received GH treatment, 1 mg/m(2)/day (≅ 0.035 mg/kg/d).

MAIN OUTCOME MEASURES

BMDTB, BMDLS, and BMADLS was measured by using the same dual-energy x-ray absorptiometry machine for all annual measurements.

RESULTS

In the prepubertal group, BMDTB standard deviation score (SDS) and BMDLSSDS significantly increased during 4 years of GH treatment whereas BMADLSSDS remained stable. During adolescence, BMDTBSDS and BMADLSSDS decreased significantly, in girls from the age of 11 years and in boys from the ages of 14 and 16 years, respectively, but all BMD parameters remained within the normal range. Higher Tanner stages tended to be associated with lower BMDTBSDS (P = .083) and a significantly lower BMADLSSDS (P = .016). After 9 years of GH treatment, lean body mass SDS was the most powerful predictor of BMDTBSDS and BMDLSSDS in adolescents with PWS.

CONCLUSIONS

This long-term GH study demonstrates that BMDTB, BMDLS, and BMADLS remain stable in prepubertal children with PWS but decreases during adolescence, parallel to incomplete pubertal development. Based on our findings, clinicians should start sex hormone therapy from the age of 11 years in girls and 14 years in boys unless there is a normal progression of puberty.

[Familial hypercholesterolemia: why screening, counselling and treatment should be integrated]

Familial hypercholesterolemia (FH) is a monogenic autosomal dominant disorder. FH is the most common hereditary cause of raised serum cholesterol levels and is associated with an increased risk of premature cardiovascular disease (CVD). This disorder is known to have a genetic cause, and effective drug therapies exist for patients with FH. Successful cascade screening, within the framework of a national screening programme, gave the Netherlands an international role as model and pioneer as far as FH detection is concerned. With the ending of this screening programme as of 1 January 2014 the care for FH patients, including screening and counselling has had to be incorporated within the basic Dutch healthcare insurance system. It is essential that detection of FH should continue in as efficient and cost-effective a manner as possible. Our proposal is that this detection should be performed and co-ordinated by those treating patients with FH so that FH screening, counselling and treatment are integrated.

Eight years of growth hormone treatment in children with Prader-Willi syndrome: maintaining the positive effects

BACKGROUND

The most important reason for treating children with Prader-Willi syndrome (PWS) with GH is to optimize their body composition.

OBJECTIVES

The aim of this ongoing study was to determine whether long-term GH treatment can counteract the clinical course of increasing obesity in PWS by maintaining the improved body composition brought during early treatment.

SETTING

This was a multicenter prospective cohort study.

METHODS

We have been following 60 prepubertal children for 8 years of continuous GH treatment (1 mg/m(2)/d ≈ 0.035 mg/kg/d) and used the same dual-energy x-ray absorptiometry machine for annual measurements of lean body mass and percent fat.

RESULTS

After a significant increase during the first year of GH treatment (P < .0001), lean body mass remained stable for 7 years at a level above baseline (P < .0001). After a significant decrease in the first year, percent fat SD score (SDS) and body mass index SDS remained stable at a level not significantly higher than at baseline (P = .06, P = .14, resp.). However, body mass index SDSPWS was significantly lower after 8 years of GH treatment than at baseline (P < .0001). After 8 years of treatment, height SDS and head circumference SDS had completely normalized. IGF-1 SDS increased to +2.36 SDS during the first year of treatment (P < .0001) and remained stable since then. GH treatment did not adversely affect glucose homeostasis, serum lipids, blood pressure, and bone maturation.

CONCLUSION

This 8-year study demonstrates that GH treatment is a potent force for counteracting the clinical course of obesity in children with PWS.

Beneficial effects of growth hormone treatment on cognition in children with Prader-Willi syndrome: a randomized controlled trial and longitudinal study

BACKGROUND

Knowledge about the effects of GH treatment on cognitive functioning in children with Prader-Willi syndrome (PWS) is limited.

METHODS

Fifty prepubertal children aged 3.5 to 14 yr were studied in a randomized controlled GH trial during 2 yr, followed by a longitudinal study during 4 yr of GH treatment. Cognitive functioning was measured biennially by short forms of the WPPSI-R or WISC-R, depending on age. Total IQ (TIQ) score was estimated based on two subtest scores.

RESULTS

During the randomized controlled trial, mean sd scores of all subtests and mean TIQ score remained similar compared to baseline in GH-treated children with PWS, whereas in untreated controls mean subtest sd scores and mean TIQ score decreased and became lower compared to baseline. This decline was significant for the Similarities (P = 0.04) and Vocabulary (P = 0.03) subtests. After 4 yr of GH treatment, mean sd scores on the Similarities and Block design subtests were significantly higher than at baseline (P = 0.01 and P = 0.03, respectively), and scores on Vocabulary and TIQ remained similar compared to baseline. At baseline, children with a maternal uniparental disomy had a significantly lower score on the Block design subtest (P = 0.01) but a larger increment on this subtest during 4 yr of GH treatment than children with a deletion. Lower baseline scores correlated significantly with higher increases in Similarities (P = 0.04) and Block design (P < 0.0001) sd scores.

CONCLUSIONS

Our study shows that GH treatment prevents deterioration of certain cognitive skills in children with PWS on the short term and significantly improves abstract reasoning and visuospatial skills during 4 yr of GH treatment. Furthermore, children with a greater deficit had more benefit from GH treatment.

Genotype-phenotype analysis in congenital adrenal hyperplasia due to P450 oxidoreductase deficiency

CONTEXT

P450 oxidoreductase deficiency (PORD) is a unique congenital adrenal hyperplasia variant that manifests with glucocorticoid deficiency, disordered sex development (DSD), and skeletal malformations. No comprehensive data on genotype-phenotype correlations in Caucasian patients are available.

OBJECTIVE

The objective of the study was to establish genotype-phenotype correlations in a large PORD cohort.

DESIGN

The design of the study was the clinical, biochemical, and genetic assessment including multiplex ligation-dependent probe amplification (MLPA) in 30 PORD patients from 11 countries.

RESULTS

We identified 23 P450 oxidoreductase (POR) mutations (14 novel) including an exonic deletion and a partial duplication detected by MLPA. Only 22% of unrelated patients carried homozygous POR mutations. p.A287P was the most common mutation (43% of unrelated alleles); no other hot spot was identified. Urinary steroid profiling showed characteristic PORD metabolomes with variable impairment of 17α-hydroxylase and 21-hydroxylase. Short cosyntropin testing revealed adrenal insufficiency in 89%. DSD was present in 15 of 18 46,XX and seven of 12 46,XY individuals. Homozygosity for p.A287P was invariably associated with 46,XX DSD but normal genitalia in 46,XY individuals. The majority of patients with mild to moderate skeletal malformations, assessed by a novel scoring system, were compound heterozygous for missense mutations, whereas nearly all patients with severe malformations carried a major loss-of-function defect on one of the affected alleles.

CONCLUSIONS

We report clinical, biochemical, and genetic findings in a large PORD cohort and show that MLPA is a useful addition to POR mutation analysis. Homozygosity for the most frequent mutation in Caucasians, p.A287P, allows for prediction of genital phenotype and moderate malformations. Adrenal insufficiency is frequent, easily overlooked, but readily detected by cosyntropin testing.

Efficacy and safety of long-term continuous growth hormone treatment in children with Prader-Willi syndrome

BACKGROUND

Children with Prader-Willi syndrome (PWS) have abnormal body composition and impaired growth. Short-term GH treatment has beneficial effects.

OBJECTIVES

The aim of the study was to investigate effects of long-term continuous GH treatment on body composition, growth, bone maturation, and safety parameters.

SETTING

We conducted a multicenter prospective trial.

DESIGN

Fifty-five children with a mean +/- sd age of 5.9 +/- 3.2 yr were followed during 4 yr of continuous GH treatment (1 mg/m(2) . d). Data were annually obtained in one center: fat percentage (fat%) and lean body mass (LBM) by dual-energy x-ray absorptiometry, height, weight, head circumference, bone age, blood pressure, and fasting IGF-I, IGF binding protein-3, glucose, insulin, glycosylated hemoglobin, total cholesterol, high-density lipoprotein, and low-density lipoprotein. sd scores (SDS) were calculated according to Dutch and PWS reference values (SDS and SDS(PWS)).

RESULTS

Fat%SDS was significantly lower after 4 yr of GH treatment (P < 0.0001). LBMSDS significantly increased during the first year (P = 0.02) but returned to baseline values the second year and remained unchanged thereafter. Mean +/- sd height normalized from -2.27 +/- 1.2 SDS to -0.24 +/- 1.2 SDS (P < 0.0001). Head circumference SDS increased from -0.79 +/- 1.0 at start to 0.07 +/- 1.1 SDS after 4 yr. BMISDS(PWS) significantly decreased. Mean +/- sd IGF-I and the IGF-I/IGF binding protein-3 ratio significantly increased to 2.08 +/- 1.1 and 2.32 +/- 0.9 SDS, respectively. GH treatment had no adverse effects on bone maturation, blood pressure, glucose homeostasis, and serum lipids.

CONCLUSIONS

Our study in children with PWS shows that 4 yr of continuous GH treatment (1 mg/m(2) . d) improves body composition by decreasing fat%SDS and stabilizing LBMSDS and head circumference SDS and normalizes heightSDS without adverse effects. Thus, long-term continuous GH treatment is an effective and safe therapy for children with PWS.

Smith-Lemli-Opitz syndrome and the DHCR7 gene

Smith-Lemli-Opitz syndrome, a severe developmental disorder associated with multiple congenital anomalies, is caused by a defect of cholesterol biosynthesis. Low cholesterol and high concentrations of its direct precursor, 7-dehydrocholesterol, in plasma and tissues are the diagnostic biochemical hallmarks of the syndrome. The plasma sterol concentrations correlate with severity and disease outcome. Mutations in the DHCR7 gene lead to deficient activity of 7-dehydrocholesterol reductase (DHCR7), the final enzyme of the cholesterol biosynthetic pathway. The human DHCR7 gene is localised on chromosome 11q13 and its structure has been characterized. Ninety-one different mutations in the DHCR7 gene have been published to date. This paper is a review of the clinical, biochemical and molecular genetic aspects.

Novel mutations in the 7-dehydrocholesterol reductase gene of 13 patients with Smith--Lemli--Opitz syndrome

Smith--Lemli--Opitz syndrome (SLOS) is caused by mutations in the DHCR7 gene leading to deficient activity of 7-dehydrocholesterol reductase (DHCR7; EC 1.3.1.21), the final enzyme of the cholesterol biosynthetic pathway, resulting in low cholesterol and high concentrations of its direct precursor 7-dehydrocholesterol in plasma and tissues. We here report mutations identified in the DHCR7 gene of 13 children diagnosed with SLOS by clinical and biochemical criteria. We found a high frequency of the previously described IVS8--1 G > C splice acceptor site mutation (two homozygotes, eight compound heterozygotes). In addition, 13 missense mutations and one splice acceptor mutation were detected in eleven patients with a mild to moderate SLOS-phenotype. The mutations include three novel missense mutations (W182L, C183Y, F255L) and one novel splice acceptor site mutation (IVS8--1 G > T). Two patients, homozygous for the IVS8--1 G > C mutation, presented with a severe clinical phenotype and died shortly after birth. Seven patients with a mild to moderate SLOS-phenotype disclosed compound heterozygosity of the IVS8--1 G > C mutation in combination with different novel and known missense mutations.

Simvastatin. A new therapeutic approach for Smith-Lemli-Opitz syndrome

The Smith-Lemli-Opitz syndrome (SLOS) is caused by deficient Delta(7)-dehydrocholesterol reductase, which catalyzes the final step of the cholesterol biosynthetic pathway, resulting in low cholesterol and high concentrations of its direct precursors 7-dehydrocholesterol (7DHC) and 8DHC. We hypothesized that i) 7DHC and 8DHC accumulation contributes to the poor outcome of SLOS patients and ii) blood exchange transfusions with hydroxymethylglutaryl (HMG)-CoA reductase inhibition would improve the precursor-to-cholesterol ratio and may improve the clinical outcome of SLO patients. First, an in vitro study was performed to study sterol exchange between plasma and erythrocyte membranes. Second, several exchange transfusions were carried out in vivo in two SLOS patients. Third, simvastatin was given for 23 and 14 months to two patients. The in vitro results illustrated rapid sterol exchange between plasma and erythrocyte membranes. The effect of exchange transfusion was impressive and prompt but the effect on plasma sterol levels lasted only for 3 days. In contrast, simvastatin treatment for several months demonstrated a lasting improvement of the precursor-to-cholesterol ratio in plasma, erythrocyte membranes, and cerebrospinal fluid (CSF). Plasma precursor concentrations decreased to 28 and 33% of the initial level, respectively, whereas the cholesterol concentration normalized by a more than twofold increase. During the follow-up period all morphometric parameters improved. The therapy was well tolerated and no unwanted clinical side effects occurred. This is the first study in which the blood cholesterol level in SLOS patients is normalized with a simultaneous significant decrease in precursor levels. There was a lasting biochemical improvement with encouraging clinical improvement. Statin therapy is a promising novel approach in SLOS that deserves further studies in larger series of patients.

Smith-Lemli-Opitz syndrome is caused by mutations in the 7-dehydrocholesterol reductase gene

Smith-Lemli-Opitz syndrome is a frequently occurring autosomal recessive developmental disorder characterized by facial dysmorphisms, mental retardation, and multiple congenital anomalies. Biochemically, the disorder is caused by deficient activity of 7-dehydrocholesterol reductase, which catalyzes the final step in the cholesterol-biosynthesis pathway-that is, the reduction of the Delta7 double bond of 7-dehydrocholesterol to produce cholesterol. We identified a partial transcript coding for human 7-dehydrocholesterol reductase by searching the database of expressed sequence tags with the amino acid sequence for the Arabidopsis thaliana sterol Delta7-reductase and isolated the remaining 5' sequence by the "rapid amplification of cDNA ends" method, or 5'-RACE. The cDNA has an open reading frame of 1,425 bp coding for a polypeptide of 475 amino acids with a calculated molecular weight of 54.5 kD. Heterologous expression of the cDNA in the yeast Saccharomyces cerevisiae confirmed that it codes for 7-dehydrocholesterol reductase. Chromosomal mapping experiments localized the gene to chromosome 11q13. Sequence analysis of fibroblast 7-dehydrocholesterol reductase cDNA from three patients with Smith-Lemli-Opitz syndrome revealed distinct mutations, including a 134-bp insertion and three different point mutations, each of which was heterozygous in cDNA from the respective parents. Our data demonstrate that Smith-Lemli-Opitz syndrome is caused by mutations in the gene coding for 7-dehydrocholesterol reductase.

[Three hypotonic neonates with hypertrophic cardiomyopathy: Pompe's disease]

Three neonatal patients, one girl and two boys, presented with infantile Pompe's disease. A generalized hypotonia with decreased tendon reflexes and heart failure due to hypertrophic cardiomyopathy dominated the clinical picture in all three; these symptoms are uniformly and characteristically present. This autosomal recessive glycogen storage disease is caused by a deficiency of lysosomal alpha-glucosidase. The diagnosis, suspected on the basis of the characteristic clinical picture and the results of simple laboratory tests, is made by measurement of the enzymatic activity or DNA analysis. Most patients die in their first year of life, no treatment being available.

Pitfalls in measuring plasma cholesterol in the Smith–Lemli–Opitz syndrome

Correct quantitative results for plasma cholesterol, 7-dehydrocholesterol (7-DHC), and 8-dehydrocholesterol (8-DHC) are invaluable for making the correct diagnosis in patients with the Smith–Lemli–Opitz syndrome (SLO) and for biochemical monitoring of these patients during therapy. The enzymatic method for cholesterol measurement based on cholesterol oxidase gives falsely high values for plasma cholesterol in samples from patients with SLO. Both 7-DHC and 8-DHC contribute substantially to the test result, given that they are accepted substrates of cholesterol oxidase. All cholesterol methods making use of this enzyme are expected to give unreliable results with plasma samples from SLO patients. Cholesterol values found with these methods may be low-normal in individual cases with SLO. Therefore, other techniques for measuring cholesterol, 7-DHC, and 8-DHC, e.g., gas chromatography, should be used for diagnosing these patients and for follow-up during therapy. However, a normal value for plasma cholesterol, as obtained by gas chromatography, does not exclude SLO. The diagnosis should always be confirmed or excluded by testing for the presence of high concentrations of 7-DHC and 8-DHC in plasma. We found that one patient with a severe form of the disease had a plasma cholesterol concentration of 20 μmol/L—to our knowledge, the lowest value ever recorded in a human being.

Pitfalls in measuring plasma cholesterol in the Smith-Lemli-Opitz syndrome

Correct quantitative results for plasma cholesterol, 7-dehydrocholesterol (7-DHC), and 8-dehydrocholesterol (8-DHC) are invaluable for making the correct diagnosis in patients with the Smith-Lemli-Opitz syndrome (SLO) and for biochemical monitoring of these patients during therapy. The enzymatic method for cholesterol measurement based on cholesterol oxidase gives falsely high values for plasma cholesterol in samples from patients with SLO. Both 7-DHC and 8-DHC contribute substantially to the test result, given that they are accepted substrates of cholesterol oxidase. All cholesterol methods making use of this enzyme are expected to give unreliable results with plasma samples from SLO patients. Cholesterol values found with these methods may be low-normal in individual cases with SLO. Therefore, other techniques for measuring cholesterol, 7-DHC, and 8-DHC, e.g., gas chromatography, should be used for diagnosing these patients and for follow-up during therapy. However, a normal value for plasma cholesterol, as obtained by gas chromatography, does not exclude SLO. The diagnosis should always be confirmed or excluded by testing for the presence of high concentrations of 7-DHC and 8-DHC in plasma. We found that one patient with a severe form of the disease had a plasma cholesterol concentration of 20 micromol/L-to our knowledge, the lowest value ever recorded in a human being.

[Theophylline poisoning in children]

Three infants aged 1, 3 and 9 months with severe theophylline intoxication are reported. Maximum serum theophylline concentrations were 65, 44 and 156 mg/l, respectively. Vomiting, agitation and tachycardia are the classical features. Seizures and cardiac arrhythmias suggest severe intoxication. The third patient underwent immediate peritoneal dialysis. All patients survived and recovered without sequelae. Haemoperfusion is considered to be the definite treatment for severe forms of theophylline intoxication.

[Smith-Lemli-Opitz syndrome; a special defect in cholesterol metabolism]

In a male neonate dysmaturity, microcephalia, a high nasal bridge, a long philtrum, broad dental ridges, schisis of the palatum molle, retrognathia, a small penis with a chorda, a small scrotum, bilateral inguinal hernia and bilateral syndactyly of the second and third toes were observed. The presence of the Smith-Lemli-Opitz (SLO) syndrome was suspected. By gas chromatography a severely decreased plasma cholesterol level (0.27 mmol/l) was found and an increased plasma 7-dehydrocholesterol level (0.24 mmol/l). The SLO syndrome is caused by a block in the cholesterol biosynthesis due to the autosomal recessive deficiency of 7-dehydrocholesterol reductase. The patient's condition improved with use of a cholesterol-enriched diet.