E.E.J. De Bruyn

Guidelines for the Assessment Process (GAP): A Proposal for Discussion

Summary: Current existing or proposed standards and guidelines in the field of psychological assessment are confined to psychological tests and psychological testing. But tests constitute only one category of psychological assessment procedures, and testing is only one of many available strategies or classes of actions in the course of the assessment process. Tests and testing are closely linked to a certain approach to psychological assessment, i. e., the psychometric one. This is one reason why it is relatively easy to formulate and establish standards or guidelines in the case of psychological tests and testing. The much more comprehensive assessment process is an indispensable part of any approach to psychological assessment, even of those that do not use psychometric tests. This makes the formulation of guidelines for the assessment process an ambitious and very difficult enterprise. But it can be done, at least at the level of recommendations that could help the assessor to cope with the complexitie...

Predictive testing for cognitive functioning in female carriers of the fragile X syndrome using hair root analysis

The fragile X syndrome, the most common form of hereditary cognitive impairment, with a frequency of 1:4000 males and 1:6000 females, is caused by expansion of a trinucleotide repeat (CGG) within the FMR1 gene.1 In the normal population, the length varies from five to 50 repeats.2 Subjects with the fragile X syndrome have more than 200 CGG repeats (full mutation, FM) and, as a consequence, the FMR1 promoter region, including the CGG repeat, is hypermethylated.3,4 As methylation results in a lack of FMR1 gene transcription, no FMR1 protein (FMRP) is produced. The absence of FMRP in the brain (neurones) is responsible for the cognitive impairment in the fragile X syndrome.5,6 In addition, some subjects have intermediate sized alleles of between 50 and 200 CGG repeats (premutations; PM). The PM alleles are unmethylated with normal FMRP biosynthesis, but are unstable during transmission to the next generation. Male fragile X patients are characterised by mild to severe learning difficulties. Macro-orchidism and facial abnormalities, including a long face with large, prominent ears and behavioural features such as hyperactivity, poor eye contact, and hand flapping, may be part of the fragile X phenotype in males. Generally, there is wide variation in the degree of clinical involvement in female FM carriers. Approximately 60% of females carriers have mild to moderate mental impairment, while the remaining 40% have normal intellectual capacity. The molecular basis for the phenotypic variability in both males and females is believed to be linked to the variable number of neurones in the brain that express FMRP. Mosaic males who are affected show a variable combination of PM and FM alleles, but the usual predominance of FM.7 In female carriers of FM, variation in the X chromosome inactivation ratio may account for the clinical variability in …