M. E. Rubio-Gozalbo

Gonadal function in male and female patients with classic galactosemia

BACKGROUND Hypergonadotropic hypoestrogenic infertility is the most burdensome complication for females suffering from classic galactosemia. In contrast, male gonadal function seems less affected. The underlying mechanism is not understood and several pathogenic mechanisms have been proposed. Timing of the lesion, prenatal or chronic post-natal, or a combination of both are not yet clear. METHODS This review focuses on gonadal function in males and females, ovarian imaging and histology in this disease. It is based on the literature known to the authors and a Pubmed search using the keywords galactosemia, GALT deficiency, (premature) ovarian failure/insufficiency/dysfunction, testicular function, gonadotrophins, FSH, LH (published between January 1971 and April 2009). RESULTS Male gonads are less affected, boys spontaneously reach puberty, although onset can be delayed. Semen quality has not been extensively studied. Several affected males are known to have fathered a child. Female gonads are invariably affected, although to a varied extent (hypergonadotropic hypoestrogenic ovarian dysfunction). Intriguingly, FSH is often already increased in infancy. Imaging usually shows hypoplastic and streak-like ovaries. Histological findings in some cases reveal the presence of morphologically normal but decreased numbers of primordial follicles, with the absence of intermediate and Graafian follicles. CONCLUSION Gonads in males seem less affected than in females who exhibit hypergonadotropic hypoestrogenic subfertility. FSH can be elevated in infancy, and ovarian histology sometimes shows the presence of normal primordial follicles with absence of intermediate and Graafian follicles. These findings are similar to other genetic diseases primarily affecting the ovary.

Chip-based mtDNA mutation screening enables fast and reliable genetic diagnosis of OXPHOS patients

Purpose: Oxidative phosphorylation is under dual genetic control of the nuclear and the mitochondrial DNA (mtDNA). Oxidative phosphorylation disorders are clinically and genetically heterogeneous, which makes it difficult to determine the genetic defect, and symptom-based protocols which link clinical symptoms directly to a specific gene or mtDNA mutation are falling short. Moreover, approximately 25% of the pediatric patients with oxidative phosphorylation disorders is estimated to have mutations in the mtDNA and a standard screening approach for common mutations and deletions will only explain part of these cases. Therefore, we tested a new CHIP-based screening method for the mtDNA.Methods: MitoChip (Affymetrix) resequencing was performed on three test samples and on 28 patient samples.Results: Call rates were 94% on average and heteroplasmy detection levels varied from 5–50%. A genetic diagnosis can be made in almost one-quarter of the patients at a potential output of 8 complete mtDNA sequences every 4 days. Moreover, a number of potentially pathogenic unclassified variants (UV) were detected.Conclusions: The availability of long-range PCR protocols and the predominance of single nucleotide substitutions in the mtDNA make the resequencing CHIP a very fast and reliable method to screen the complete mtDNA for mutations.

Termination of damaged protein repair defines the occurrence of symptoms in carriers of the m.3243A>G tRNA Leu mutation.

Background: The m.3243A>G mutation in the mitochondrial tRNALeu(UUR) gene is an example of a mutation causing a very heterogeneous phenotype. It is the most frequent cause (80%) of the MELAS syndrome (mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes), but it can also lead in addition or separately to type 2 diabetes, deafness, renal tubulopathy and/or cardiomyopathy. Methods: To identify pathogenic processes induced by this mutation, we compared global gene expression levels of muscle biopsies from affected and unaffected mutation carriers with controls. Results and conclusions: Gene expression changes were relatively subtle. In the asymptomatic group 200 transcripts were upregulated and 12 were downregulated, whereas in the symptomatic group 15 transcripts were upregulated and 52 were downregulated. In the asymptomatic group, oxidative phosphorylation (OXPHOS) complex I and IV genes were induced. Protein turnover and apoptosis were elevated, most likely due to the formation of dysfunctional and reactive oxygen species (ROS) damaged proteins. These processes returned to normal in symptomatic patients. Components of the complement system were upregulated in both groups, but the strongest in the symptomatic group, which might indicate muscle regeneration—most likely, protein damage and OXPHOS dysfunction stimulate repair (protein regeneration) and metabolic adaptation (OXPHOS). In asymptomatic individuals these processes suffice to prevent the occurrence of symptoms. However, in affected individuals the repair process terminates, presumably because of excessive damage, and switches to muscle regeneration, as indicated by a stronger complement activation. This switch leaves increasingly damaged tissue in place and muscle pathology becomes manifest. Therefore, the expression of complement components might be a marker for the severity and progression of MELAS clinical course.

Psychosocial developmental milestones in men with classic galactosemia

Patients with classic galactosemia suffer from several long term effects of their disease. Research in a group of mainly female patients has shown that these patients may also have a developmental delay with regard to their social aptitude. To study if male galactosemia patients achieve psychosocial developmental milestones more slowly than male peers from the general Dutch population, we assessed their development with the Course of Life Questionnaire (CoLQ). A total of 18 male galactosemia patients participated in this study (response rate 69%): 11 Dutch patients and seven American patients. We found severe delays in the social and psychosexual scales of this questionnaire, but not on the autonomy axis. These results are comparable to an earlier study with a limited number of male patients. The observed delays could be secondary to less developed social skills, cognitive dysfunction, or disrupted language development. We strongly recommend screening of galactosemia patients for developmental delays, to ensure early intervention through social skills training.

The galactosemia network (GalNet)

The three main determinants for a significant research activity level in a rare disease are the existence of patient organizations, patient registries and international networks. In line with this an international network for the galactosemias—GalNet—was established in 2012 (www.galactosemianetwork.org). It includes professionals from 18 European countries, Israel, the United States and Australia and it was founded with the financial support of the European Galactosemia Patient Society and several national grants. Our activities are funded with grants from different national organizations. This network is not linked to a pharmaceutical or nutritional company. The GalNet focuses on the advancement of research, diagnosis, treatment and follow-up care of galactosemic patients by close collaboration among clinicians, basic researchers, nutritionists and patient associations. It is open for clinicians and researchers from all countries in order to improve the care of patients worldwide. Centers not already participating but willing to do so, are invited to join the network. The main objectives are the development and implementation of a patient registry; elaboration of guidelines for diagnosis, treatment and follow up and transnational collaborative research. Registry: GalNet has developed and implemented a webbased international patient Registry (http://www.orpha. net/consor/cgi-bin/OC_Exp.php?lng=GB&Expert=443949) according to the standards set by the European Platform on Rare Diseases Registration. It aims to delineate the clinical history of patients, to provide information on many different aspects of the galactosemias, to help generate new hypotheses based on a large dataset of patients, and ultimately to serve as a platform for clinical trials. At present, several participating countries are performing data entry and by September 2016, 177 patients were entered. To participate in the registry centres are required to obtain Ethics approval. Guidelines: There is a great diversity in the diagnosis, treatment and follow-up of patients for classic galactosemia, and presumed also for the other galactosemias. Within

Neuroleptic malignant syndrome during zuclopenthixol therapy in X-linked cerebral adrenoleukodystrophy.

An 8 year-old boy with X-ALD under treatment with simvastatin developed a severe adverse reaction when the dose of his other medication, zuclopenthixol was increased. Both drugs were withdrawn after a diagnosis of neuroleptic malignant syndrome was made.

Childhood Pompe disease: Clinical spectrum and genotype in 31 children

G.P.11 Characteristic skeletal muscle imaging patterns in Japanese patients with Pompe disease K. Ishigaki *, H. Kobayashi , H. Sugie , T. Fukuda , T. Murakami , T. Sato , K. Ishiguro , M. Shichiji , S. Nagata , M. Osawa , Y. Eto , I. Nonaka 6 1 Tokyo Women’s Medical University, School of Medicine, Pediatrics, Tokyo, Japan; 2 The Jikei University, School of Medicine, Pediatrics, Tokyo, Japan; 3 Tokoha University, Occupational Therapy, Medical Science, Hamamatsu, Japan; 4 Hamamatsu University, School of Medicine, Pediatrics, Hamamatsu, Japan; 5 Advanced Clinical Research Center, Institute of Neurological Disorders, Kawasaki, Japan; 6 National Center of Neurology and Psychiatry, Tokyo, Japan