Development of the phenylketonuria screening programme in Estonia

Abstract

Objective-To develop the phenylketonuria (PKU) screening programme in Estonia. Method-All data about patients with PKU, born during 1980-92, were documented to establish its prevalence at birth in Estonia. Newborn screening for the diagnosis and treatment of PKU was started in Estonia in 1993 and the prevalence at birth established by screening. Phenylalanine was determined from filter paper blood by a modified fluorometric method based on enhancement of the fluorescence of a phenylalanine-ninhydrin reaction product by L-leucyl-L-alanine. Results-During three years (1993-5) 36 074 newborns (85% of the total) were screened for PKU. PKU was diagnosed in six cases during the first four to six weeks of life. All investigated cases could be classified as classical PKU. No cases of mild forms of hyperphenylalaninaemia were diagnosed. The retrospective study showed an average incidence of PKU of 1 in 8090, the prospective study identified a comparable incidence of 1 in 6010 live births. Conclusion-The prevalence at birth of classic PKU in Estonia is higher than the average in Europe and similar to that of some eastern and middle European countries. (J Med Screen 1998;5:22-23)

Association between minihaplotypes and mutations at the phenylalanine hydroxylase locus in Latvian phenylketonuria patients

“…The most common mutation R408W accounts for 73% of Latvian PKU chromosomes. The same prevalence of this mutation is found in the Lithuanian population (Kasnauskiene et al, 2003) and is even higher (84%) in the Estonian population (Ounap et al, 1998).…”

“…Mutation R408W was almost exclusively associated with minihaplotype 3/238, although it was found in association with four minihaplotypes: 3/238 (82.4%), 3/242 (8.8%), 3/234 (5.9%) and 8/238 (2.9%). Minihaplotype 3/238 is also the main minihaplotype for mutation R408W in Estonian, Polish and German populations (Ounap et al, 1998;Zekanowski et al, 2001;Zschocke et al, 1999). It is also found in the Irish PKU population but in significantly lower frequencies (15%) compared with the minihaplotype 8/242, which is predominant (81.7%) minihaplotype for R408W (O'Donnell et al, 2002).…”

FLAD1‐associated multiple acyl‐CoA dehydrogenase deficiency identified by newborn screening

“…We here describe a case of FLAD1 ‐associated MADD diagnosed after a positive newborn screening result. In Estonia, newborn screening for phenylketonuria was introduced in 1993 (Ounap, Lillevali, Metspalu, & Lipping‐Sitska, ), and in 1996 screening for congenital hypothyroidism was added. In 2014, expanded neonatal screening was initiated and presently includes 19 treatable congenital metabolic diseases (Reinson et al, ).…”

The Live-Birth Prevalence of Mucopolysaccharidoses in Estonia

“…Therefore, we can assume that we have not missed any cases over 21 years, which, in our opinion, is quite a prolonged period for calculating the prevalence of a rare disorder in a small population such as Estonia. MPSs account for more than one tenth of all diagnosed patients with inborn errors of metabolism (IEM) in Estonia (data not shown), and MPS is the third most frequent inherited metabolic disease after phenylketonuria-1:6010 (Ounap et al, 1998) and galactosemia-1:19,700 (Õ unap et al, 2010).…”