Preventing maternal phenylketonuria (PKU) syndrome: important factors to achieve good metabolic control throughout pregnancy.

BACKGROUND: Insufficient metabolic control during pregnancy of mothers with phenylketonuria (PKU) leads to maternal PKU syndrome, a severe embryo-/fetopathy. Since maintaining or reintroducing the strict phenylalanine (Phe) limited diet in adults with PKU is challenging, we evaluated the most important dietary and psychosocial factors to gain and sustain good metabolic control in phenylketonuric women throughout pregnancy by a questionnaire survey with 38 questions concerning therapy feasibility. Among them, the key questions covered 5 essential items of PKU care as follows: General information about maternal PKU, PKU training, diet implementation, individual metabolic care, personal support. In addition, all participating PKU mothers were asked to estimate the quality of their personal metabolic control of the concluded pregnancies. 54 PKU mothers with 81 pregnancies were approached at 12 metabolic centers in Germany and Austria were included. According to metabolic control, pregnancies of PKU women were divided in two groups: group "ideal" (not more than 5% of all blood Phe concentrations during pregnancy > 360 µmol/l; n = 23) and group "suboptimal" (all others; n = 51). RESULTS: The demand for support was equally distributed among groups, concerning both amount and content. Personal support by the direct social environment (partner, family and friends) ("suboptimal" 71% vs "ideal" 78%) as well as individual metabolic care by the specialized metabolic center (both groups around 60%) were rated as most important factors. The groups differed significantly with respect to the estimation of the quality of their metabolic situation (p < 0.001). Group "ideal" presented a 100% realistic self-assessment. In contrast, group "suboptimal" overestimated their metabolic control in 53% of the pregnancies. Offspring of group "suboptimal" showed clinical signs of maternal PKU-syndrome in 27%. CONCLUSION: The development of training programs by specialized metabolic centers for females with PKU in child bearing age is crucial, especially since those mothers at risk of giving birth to a child with maternal PKU syndrome are not aware of their suboptimal metabolic control. Such programs should provide specific awareness training for the own metabolic situation and should include partners and families.

Misregulation of mitotic chromosome segregation in a new type of autosomal recessive primary microcephaly.

Primary autosomal recessive microcephaly (MCPH) is a congenital disorder characterized by a pronounced reduction of brain size and mental retardation. We present here a consanguineous Turkish family clinically diagnosed with MCPH and without linkage to any of the known loci (MCPH1-MCPH7). Autozygosity mapping identified a homozygous region of 15.8 Mb on chromosome 10q11.23-21.3, most likely representing a new locus for MCPH. Although we were unable to identify the underlying genetic defect after extensive molecular screening, we could delineate a possible molecular function in chromosome segregation by the characterization of mitosis in the patients' cells. Analyses of chromosome nondisjunction in T-lymphocytes and fibroblasts revealed a significantly elevated rate of nondisjunction in the patients' cells as compared to controls. Mitotic progression was further explored by immunofluorescence analyses of several chromosome and spindle associated proteins. We detected a remarkable alteration in the anaphase distribution of Aurora B and INCENP, which are key regulators of chromosome segregation. In particular, a fraction of both proteins remained abnormally loaded on chromosomes during anaphase in MCPH patients' cells while in cells of normal control subjects both proteins are completely transferred to the spindle midzone. We did not observe any other alterations regarding cell cycle progression, chromosome structure, or response to DNA damage. Our observations point towards a molecular role of the underlying gene product in the regulation of anaphase/telophase progression possibly through interaction with chromosomal passenger proteins. In addition, our findings represent further evidence for the proposed role of MCPH genes in the regulation of mitotic progression.