Intellectual performance of children with maple syrup urine disease

The intellectual performance of 22 children aged 3–16 years with maple syrup urine disease (MSUD) was assessed and compared to a group of early treated phenylketonuria (PKU) children and normal subjects matched by age, sex, nationality, and socio-economic status. All subjects were tested by one examiner only using the age related versions of the non-verbal Snijders-Oomen intelligence test. The mean IQ (±SD) score was 74±14 (range 50–103) in patients with MSUD, 101±12 (range 87–125) in early treated PKU patients, and 107±9 (range 90–122) in normal subjects. Intercorrelations indicated that length of time after birth that plasma leucine concentration remained >1 mmol/l and quality of long-term metabolic control have important influences on IQ.     

“PKU Bodies”: Characteristic inclusions in the brain in phenylketonuria

Summary The ultrastructure of various inclusions within oligodendroglial cells in the brains from two phenylketonuric patients was studied. Characteristic lamellar, oval, slightly irregular inclusions measured between 0.5 and 2 micra in diameter and were bounded by a single membrane. The longitudinal and transverse lamellae of these inclusions had a distinct pattern. In analogy to lamellated but different inclusions of other diseases, these structures were termed PKU bodies. Various possibilities that would explain the morphogenesis of the PKU bodies and other inclusions in the oligodendroglial cells, and the significance of these findings, are discussed.     

Biochemical control,genetic analysis and magnetic resonance imaging in patients with phenylketonuria

Thirteen patients with phenylketonuria, detected by neonatal screening and started on diet within 16 days of age, were investigated between 10 and 18 years of age by magnetic resonance imaging (MRI) of the brain. Biochemical control was assessed from: (1) the life time blood phenylalanine (Phe) control (as determined from (a) the mean yearly exposure to Phe; (b) the accumulated time for each patient that Phe was <120 mol/l; (c)>400 mol/l; (d)>800 mol/l; and (e)>1200 mol/l); and (2) the blood Phe control over the 5 years prior to imaging (assessed for each patient by the mean yearly Phe exposure over that period). In all patients the phenylalanine hydroxylase gene locus was studied using restriction fragment length polymorphism haplotypes and mutant genes were screened for a variety of specific mutations which have been reported in other European populations or in populations of north European descent. Two patients had significant abnormalities of cerebral white matter. Although both showed poor biochemical control this did not reach statistical significance when compared to those with normal imaging. DNA haplotype patterns could be assigned to 11 patients and mutant genes were identified in 12. One patient with abnormal imaging and 4 patients without abnormalities had mutations on both chromosomes identified. In these 5 patients there was significant correlation between their genotype and biochemical control. Mutations resulting in residual in vitro enzyme activity were associated with normal imaging.     

Prevalence of sleep disorders in early-treated phenylketonuric children and adolescents. Correlation with dopamine and serotonin status

Phenylketonuric (PKU) patients are a population at risk for sleep disorders due to deficits in neurotransmitter synthesis. We aimed to study the prevalence of sleep disorders in early-treated PKU children and adolescents and assessed correlations with dopamine and serotonin status. We compared 32 PKU patients (16 females, 16 males; mean age 12 years), with a healthy control group of 32 subjects (16 females, 16 males; mean age 11.9 years). 19 PKU patients were under dietary treatment and 13 on tetrahydrobiopterin therapy. Concurrent phenylalanine (Phe), index of dietary control and variability in Phe in the last year, tyrosine, tryptophan, prolactin, and ferritin in plasma, platelet serotonin concentration, and melatonin, homovanillic and 5-hydroxyindoleacetic acid excretion in urine were analyzed. Sleep was assessed using Bruni's Sleep Disturbance Scale for Children. Sleep disorders were similar in both groups, 15.6% in control group and 12.5% in PKU group. In PKU patients, no correlations were found with peripheral biomarkers of neurotransmitter synthesis nor different Phe parameters, 43.3% had low melatonin excretion and 43.8% low platelet serotonin concentrations. Despite melatonin and serotonin deficits in early-treated PKU patients, the prevalence of sleep disorders is similar to that of the general population.     

Severe acute pancreatitis in a child with phenylketonuria

We report for the first time severe acute pancreatitis in a child treated for phenylketonuria (PKU) discovered on neonatal screening. This 2-year-old boy was first hospitalized for bilious vomiting and moderate back pain. Laboratory values included a lipase level of 1.142 U/L, a phenylalanine level of 10 mg/dL, and computed tomography revealed Balthazar grade E pancreatitis. Continuous enteral feeding was started on the 3rd day after admission. We observed clinical and biological improvement. Etiologic investigations for pancreatitis returned negative. Despite the severity of the pancreatitis, we did not observe decompensation of the metabolic disease. Specific nutritional management was necessary.     

应用等位基因特异性扩增检测经典型苯丙酮尿症PAH基因第6外显子基因突变

目的建立快速简便、特异灵敏的鉴定PAH基因第6外显子c.611A〉G突变热点的基因诊断方法。方法针对突变频率较高的PAH基因第6外显子的突变热点c.611A〉G,设计等位基因特异性扩增（amplification refractory mutationsystem,ARMS）的特异引物,对山西省已经临床确诊的70例经典型PKU患儿、c.611A〉G突变患儿的家长及50例正常儿童进行第6外显子扩增,扩增产物测序验证。结果在受检的山西省患儿中,PAH基因第6外显子c.611A〉G突变位点ARMS检测结果和测序结果完全相符。结论 ARMS技术操作简便,重复性和稳定性好,可作为PAH基因热点突变的快速灵敏检测方法。     

2002～2008年锦州市新生儿疾病筛查分析研究

目的:探讨锦州市2002～2008年新生儿疾病筛查情况,总结经验,采取措施,促进筛查工作。方法:新生儿出生后72h,采足跟末稍血制成滤纸干血片,进行筛查。结果:2002～2008年锦州市新生儿筛查83328例,确诊先天性甲状腺功能减退症(CH)30例,CH发病率1/2777;苯丙酮尿症(PKU)为6例,PKU发病率为1/13888。新生儿筛查率呈逐年上升趋势,由2002年的26.6%上升至2008年的74.6%,平均每年以6.8%的速度上升。结论:锦州市CH及PKU发病率处于稳定水平,在进行新生儿疾病筛查工作中,完善新生儿疾病筛查管理办法和技术规范,加强社会宣传力度,重视筛查工作质量,对CH和PKU患儿早期治疗可避免体格和智能发育障碍,是提高人口素质的重要措施。     

Selenium intake of infants and young children,healthy children and dietetically treated patients with phenylketonuria

In 20 healthy infants and children, 5–20 months old, the Se intake was estimated by analysing food samples by instrumental neutron activation analysis. The intake was calculated by weighing the portions offered and actually consumed. The median Se content of the food amounted to 27 ng/g wet weight (gww) and median daily Se intake to 33.5 g.The Se intake was not equally distributed over the day. About 50% of the daily Se intake was derived from the supper. The main Se sources (41%) for young children were cereal paps. Commercially, available meals (30 ng/g) contained less Se than home-made ones (50 ng/g). In nine dietetically treated patients with phenylketonuria the median Se intake amounted only to 6.9 g/day corresponding to a mean Se content of the diet of 7.9 ng/g. The main Se source in the diet was vegetables (36.3%) and 20% derived from their protein supplements.The Se intake of young children, healthy or dietetically treated, cannot be calculated accurately from tables but must be estimated by measuring the Se content of the local food because cereals and vegetables-the main Se sources-exhibit great regional variations.Abbreviations Se selenium - PKU phenylketonuria - gww gram wet weight     

四氢生物喋呤负荷试验在高苯丙氨酸血症鉴别诊断中的临床应用

目的探讨四氢生物喋呤（BH4）负荷试验在高苯丙氨酸血症（HPA）鉴别诊断中的应用价值。方法自2005年5月到2007年4月，51例HPA患儿采用口服BH4（20mg／kg）负荷试验。对其中血苯丙氨酸（Phe）浓度小于600μmol／L患儿采用口服Phe—BH4联合负荷试验，结合尿喋呤分析、血红细胞二氢喋呤还原酶（DHPR）活性测定。结果（1）在BH4负荷试验中，不同类型HPA患儿的血Phe浓度表现出各不相同的改变。51例HPA患儿中，共鉴别出5例BH4缺乏症，10例BH4反应性苯丙氨酸羟化酶（PAH）缺乏症，36例BH4无反应性苯丙氨酸羟化酶（PAH）缺乏症。（2）在17例中度苯丙酮尿症（PKU）患儿中，9例（52．9％）为BH4反应性PAH缺乏症。结论BH4负荷试验在HPA早期鉴别诊断中十分重要，部分中度PKU对BH4有反应，可使用BH4替代治疗。