Mortality in the fragile X syndrome: preliminary data

Approach to the Diagnosis of Overgrowth Syndromes

Overgrowth syndromes comprise a group of disorders associated with excessive growth and other features such as facial dysmorphism, developmental delay or intellectual disability, congenital anomalies, neurological problems and an increased risk of neoplasia. Recent advances in understanding the genetic basis of overgrowth syndromes has resulted in a move away from clinical classification to molecular classification of overgrowth syndromes. This review provides a structured clinical approach to patients with this group of disorders and includes most of the currently known overgrowth syndromes.

The relationship between autistic symptomatology and independent living skills in adolescents and young adults with fragile X syndrome

Few studies have examined the relationship between autistic symptomatology and competence in independent living skills in adolescents and young adults with fragile X syndrome (FXS). In this study, 70 individuals with FXS, aged 15-25 years, and 35 matched controls were administered direct measures of independent living skills and autistic symptomatology. Results showed that higher levels of autistic symptomatology were associated with lower levels of competence in independent living skills in individuals with FXS, but not in controls. These data indicated that the relationship between autistic symptomatology and independent living skills was syndrome-specific. Early intervention strategies that address autistic symptomatology are sorely needed to improve functional outcomes in this population.

Total body irradiation in a patient with fragile X syndrome for acute lymphoblastic leukemia in preparation for stem cell transplantation: A case report and literature review

Fragile X syndrome (FXS) is a congenital disorder caused by expansion of CGG trinucleotide repeat at the 5' end of the fragile X mental retardation gene 1 (FMR1) on the X chromosome that leads to chromosomal instability and diminished serum levels of fragile X mental retardation protein (FMRP). Afflicted individuals often have elongated features, marfanoid habitus, macroorchidism and intellectual impairment. Evolving literature suggests the condition may actually protect from malignancy while chromosomal instability would presumably elevate the risk. Increased sensitivity to ionizing radiation should also be predicted by unstable sites within the DNA. Interestingly, in this report, we detail a patient with FXS diagnosed with acute lymphoblastic leukemia treated with induction followed by subsequent cycles of hyper-CVAD (cyclophosphamide, vincristine, doxorubicin, dexamethasone) with a complete response who then was recommended to undergo peripheral stem cell transplantation. The patient underwent total body irradiation (TBI) as a component of his conditioning regimen and despite the concern of his clinicians, developed minimal acute toxicity and successful engraftment. The pertinent literature regarding irradiation of patients with FXS is also reviewed.

People with intellectual disability: what do we know about adulthood and life expectancy?

Increases in the life expectancy of people with Intellectual Disability have followed similar trends to those found in the general population. With the exception of people with severe and multiple disabilities or Down syndrome, the life expectancy of this group now closely approximates with that of the general population. Middle and old age, which until 30 years ago were not recognized in this population, are now important parts of the life course of these individuals. Older adults with Intellectual Disabilities form a small, but significant and growing proportion of older people in the community. How these persons grow older and how symptoms and complications of the underlying cause of the Intellectual Disability will influence their life expectancy is of the utmost importance.

Fragile X syndrome: an aging perspective

Cognitive and behavioral correlates of molecular variations related to the FMR1 gene have been studied rather extensively, but research about the long-term outcome in individuals with fragile X spectrum disorders remains sparse. In this review, we present an overview of aging research and recent findings in regard to cellular and clinical manifestations of aging in fragile X syndrome, and the FMR1 premutation.

Therapeutic challenges in treating patients with fragile X syndrome and neoplasia

The administration of cytotoxic therapy to patients with fragile X syndrome (FXS) presents several unique therapeutic challenges. The existence of fragile sites poses a theoretical risk of tumorigenesis and potentially increased treatment associated toxicity, however, controversy exists. We review the 42 previously reported cases of neoplasia in patients with FXS and report two novel neoplasms in patients treated with radiation therapy or combined chemoradiation. Our experience suggests that radiation therapy can be delivered safely in these patients without an expectation for increased acute/sub-acute normal tissue toxicity; however, treatment requires specialized facilities with the resources to deliver this care safely.

Cancer incidence among persons with fragile X syndrome in Finland: a population-based study

BACKGROUND

Fragile X syndrome is a common inheritable cause of intellectual disability (ID) and is characterised by a large number of CGG repeats at the gene FMR1 located on the X-chromosome. It has been reported that this genetic mechanism may protect against malignant transformations.

METHODS

We extracted from the Finnish registry on persons with ID a cohort of 302 persons with a fragile X diagnosis during 1982-1986. Follow-up for cancer incidence was performed in the Finnish Cancer Registry until the end of the year 2005.

RESULTS

There were 11 reported cancers during the mean follow-up of 21.4 years per person. The expected number of cancers based on the average Finnish population was 13.8 and no statistically significant protective effect was detected [standardised incidence ratios (SIR) 0.80, confidence interval (CI) 95% 0.40-1.4]. An increased risk for lip cancer was found (SIR 23, CI 95% 2.8-85).

CONCLUSIONS

Confirmation of hypotheses about the mechanisms linking FXS and cancer needs further research.

Applicability of a checklist for clinical screening of the fragile X syndrome

In a population of 340,000 in Southern Häme, Finland, there were 541 intellectually disabled adult males (> 16 years) known to the District Organisation for the Care of the Mentally Retarded in August 1993. Of these, 197 already had a confirmed etiological diagnosis, with 20 having the fragile X syndrome. The other 344 males were screened for the fragile X syndrome using a three-step method: a clinical checklist used by a specialist nurse, a clinical examination by a physician who was very familiar with the fragile X syndrome, and the FRAXA-locus gene test. Six new fragile X males were found. The minimum prevalence of the fragile X syndrome in the district was calculated to be 1:4400.

Fragile X (Martin-Bell) syndrome

Fragile X syndrome is a common condition resulting from a cytogenetic abnormality in the X chromosome. Mental retardation, characteristic facies, and large testes are some of the most important characteristics of the condition. The relatively high incidence of the syndrome--approximately one per thousand--the high incidence of cardiac anomalies in these individuals, the oral and facial features associated with the condition, and the paucity of reported cases in the dental literature make it particularly interesting to dentistry. Here we report the case of a 12-year-old male, including the cytogenetic and cephalometric analyses, presenting with some of the classic features and some features not commonly reported.