Mucopolysaccharidosis type IIID: 12 new patients and 15 novel mutations.

Mucopolysaccharidosis III D (Sanfilippo disease type D, MPS IIID) is a rare autosomal recessive lysosomal storage disorder previously described in only 20 patients. MPS IIID is caused by a deficiency of N-acetylglucosamine-6-sulphate sulphatase (GNS), one of the enzymes required for the degradation of heparan sulphate. So far only seven mutations in the GNS gene have been reported. The clinical phenotype of 12 new MPS IIID patients from 10 families was studied. Mutation analysis of GNS was performed in 16 patients (14 index cases). Clinical signs and symptoms of the MPS IIID patients appeared to be similar to previously described patients with MPS III. Early development was normal with onset of behavioral problems around the age of 4 years, followed by developmental stagnation, deterioration of verbal communication and subsequent deterioration of motor functions. Sequence analysis of the coding regions of the gene encoding GNS (GNS) resulted in the identification of 15 novel mutations: 3 missense mutations, 1 nonsense mutation, 4 splice site mutations, 3 frame shift mutations, 3 large deletions and 1 in-frame small deletion. They include the first missense mutations and a relatively high proportion of large rearrangements, which warrants the inclusion of quantitative techniques in routine mutation screening of the GNS gene.

A new syndrome with noncompaction cardiomyopathy, bradycardia, pulmonary stenosis, atrial septal defect and heterotaxy with suggestive linkage to chromosome 6p.

We report a three-generation family with nine patients affected by a combination of cardiac abnormalities and left isomerism which, to our knowledge, has not been described before. The cardiac anomalies include non-compaction of the ventricular myocardium, bradycardia, pulmonary valve stenosis, and secundum atrial septal defect. The laterality sequence anomalies include left bronchial isomerism, azygous continuation of the inferior vena cava, polysplenia and intestinal malrotation, all compatible with left isomerism. This new syndrome is inherited in an autosomal dominant pattern. A genome-wide linkage analysis suggested linkage to chromosome 6p24.3-21.2 with a maximum LOD score of 2.7 at marker D6S276. The linkage interval is located between markers D6S470 (telomeric side) and D6S1610 (centromeric side), and overlaps with the linkage interval in another family with heterotaxy reported previously. Taken together, the genomic region could be reduced to 9.4 cM (12 Mb) containing several functional candidate genes for this complex heterotaxy phenotype.

Kabuki syndrome: a review study of three hundred patients.

The Kabuki (make-up) syndrome identified in 1981 has been reported in more than three hundred patients. Typical findings include mild to moderate mental retardation, fetal pads, cleft palate, and characteristic facies with long palpebral fissures, everted lower lateral eyelids and arched eyebrows. Postnatal growth retardation, skeletal and visceral anomalies are present in a large percentage of patients. We review here the characteristics of this peculiar syndrome in three hundred patients.

Similar phenotype characteristics comparing familial and sporadic premature ovarian failure.

OBJECTIVE: Premature ovarian failure (POF) is characterized by secondary amenorrhea before the age of 40 years, along with repeated increased follicle-stimulating hormone and low estrogen concentrations. POF is considered a complex genetic disease with a familial presentation in 12% to 50% of cases. POF may originate from different genes and various gene-environment interactions. The aim of this study was to identify possible differences in phenotype comparing women with familial and women with sporadic POF. METHODS: A multicenter study was initiated in the Netherlands using standardized phenotyping. For each woman, medical history, menstrual cycle, and fertility and smoking status were assessed and a standardized examination was performed. Based on a detailed three-generation family history, women were identified as having either familial (defined as having at least one relative with POF) or sporadic POF. RESULTS: A total of 58 familial cases and 142 sporadic cases of POF were identified. Maternal age at menopause was significantly lower in the women with familial compared with the women with sporadic POF (41.0 +/- 7.5 and 49.7 +/- 2.6 y, respectively; P < 0.001). Sex hormone-binding globulin concentration was significantly higher in the women with familial than in the women with sporadic POF (73.6 +/- 37.1 and 55.2 +/- 26.9 nmol/L, respectively; P = 0.002). All other characteristics, such as parity, bone mineral density, and serum follicle-stimulating hormone and lipid levels were similar, as was the incidence of autoimmunity and cytogenetic abnormalities. CONCLUSIONS: Familial and sporadic POF do not differ in phenotype except for maternal menopause age and sex hormone-binding globulin concentration. Future studies are needed to unravel the genotype-phenotype interactions in POF.

Familial gigantism caused by an NSD1 mutation.

A three-generation family with autosomal dominant segregation of a novel NSD1 mutation (6605G --> A, resulting in Cys2202Tyr) is reported. Haploinsufficiency of NSD1 has been identified as the major cause of Sotos syndrome. The overgrowth condition (MIM 117550) is characterized by facial anomalies, macrocephaly, advanced bone age, and learning disabilities. Manifestations in the present family include dramatically increased height, weight, and head circumference together with a long face, large mandible, and large ears, but mental deficiency was absent.

Autosomal dominant inheritance of left ventricular outflow tract obstruction.

Most nonsyndromic congenital heart malformations (CHMs) in humans are multifactorial in origin, although an increasing number of monogenic cases have been reported recently. We describe here four new families with presumed autosomal dominant inheritance of left ventricular outflow tract obstruction (LVOTO), consisting of hypoplastic left heart (HLHS) or left ventricle (HLV), aortic valve stenosis (AS) and bicuspid aortic valve (BAV), hypoplastic aortic arch (HAA), and coarctation of the aorta (CoA). LVOTO in these families shows a wide clinical spectrum with some family members having severe anomalies such as hypoplastic left heart, and others only minor anomalies such as mild aortic valve stenosis. This supports the suggestion that all anomalies of the LVOTO spectrum are developmentally related and can be caused by a single gene defect.

Three new families with arterial tortuosity syndrome.

Arterial tortuosity syndrome (ATS) is a rare condition with autosomal recessive inheritance characterized by connective tissue abnormalities. The most specific clinical findings are cardiovascular anomalies including tortuosity, lengthening, aneurysm, and stenosis formation of major arteries. Also ventricular hypertrophy is frequently present. Other anomalies are skin hyperextensibility and cutis laxa, joint laxity or contractures of the joints, and inguinal herniae. Histology shows disruption of elastic fibers of the media. These features suggest that ATS is a connective tissue disorder. A biochemical or molecular defect has not yet been identified. We describe here nine additional ATS patients from three consanguineous Moroccan families and review a total of 35 patients with this uncommon condition.

A novel tau mutation, S320F, causes a tauopathy with inclusions similar to those in Pick's disease.

Mutations in the tau gene cause familial frontotemporal dementia and parkinsonism linked to chromosome 17. In this article, we describe a novel missense mutation, S320F, in the tau gene in a family with presenile dementia. To our knowledge, it is the first mutation to be described in exon 11 of tau. The proband died at age 53 years, after a disease duration of 15 years, and autopsy revealed a neuropathological picture similar to Pick's disease. Recombinant tau protein with the S320F mutation showed a greatly reduced ability to promote microtubule assembly.

Attitudes and distress levels in women at risk to carry a BRCA1/BRCA2 gene mutation who decline genetic testing.

Genetic testing enables women at risk for hereditary breast and/or ovarian cancer to find out whether they have inherited the gene mutation, and if so, to opt for undergoing frequent surveillance and/or prophylactic surgery. However, the option to know about one's genetic status is not always seen as a benefit by women at risk. Motives for declining genetic testing were explored in 13 women at 25% or 50% risk to be a BRCA1/BRCA2 mutation carrier, who participated in a surveillance program for breast/ovarian cancer (the non-tested group). We hypothesized that high anxiety might be an important motive to decline testing. In addition, we investigated whether the non-tested group differed from a reference group of women who did undergo the test (tested group; n = 85) with regard to biographical factors, experience with cancer in relatives, and personality traits. Most non-tested women (10/13) were satisfied with participating in the surveillance program. Four reported to feel emotionally unprepared to cope with the consequences of testing. Compared with the tested group, the non-tested women had similar mean distress levels (which were not high), but a higher education level, they were more often childless, showed more reluctance towards prophylactic surgery, were younger when first confronted with a relative affected with breast/ovarian cancer, and were longer aware of the genetic nature of the disease. This study showed that women were more likely to have thoroughly reflected on their decision not to undergo genetic testing, than to deny the whole issue due to high anxiety. Being confronted at a relatively young age with breast/ovarian cancer in a relative, and being aware of the genetic risk for a many years, may have resulted in the risk for cancer becoming an integrated part of their lives. However, generalization of these results to women who neither underwent the test nor participated in a surveillance program should be considered with caution.

One year follow-up of women opting for presymptomatic testing for BRCA1 and BRCA2: emotional impact of the test outcome and decisions on risk management (surveillance or prophylactic surgery).

Genetic testing enables women at risk for hereditary breast and/or ovarian cancer to find out whether they have inherited the gene mutation (BRCA1/BRCA2), and if so, to opt for frequent surveillance and/or prophylactic surgery (bilateral mastectomy and/or oophorectomy). Here, a follow-up is described for 63 healthy women at 50% risk of being a BRCA1/BRCA2 mutation carrier who underwent genetic testing. The course of distress and problems regarding body image and sexuality up to 1 year after disclosure of the test-outcome were described separately for mutation carriers undergoing mastectomy (n = 14), for mutation carriers opting for surveillance (n = 12) and for non-mutation carriers (n = 37). Furthermore, we analyzed whether women opting for prophylactic mastectomy differed from those opting for close surveillance with respect to biographical characteristics, experiences with cancer in relatives and personality. Women opting for prophylactic mastectomy had significantly higher distress levels than mutation carriers who opted for surveillance, and the non-mutation carriers. This difference in levels of distress was highest at pre- and post-test and had almost disappeared at 1-year follow-up. Besides, mutation carriers opting for prophylactic mastectomy were more often in their thirties, more often had young children and had a longer awareness of the genetic nature of cancer in the family than those opting for regular surveillance. Adverse effects were observed in women who underwent prophylactic mastectomy (mostly in combination with immediate breast reconstruction) regarding the perception of how their breast region looked like and felt, the intimate relationship and physical wellbeing whereas women opting for prophylactic mastectomy reported more distress than the other women in the study, their distress levels had significantly decreased 6 months or longer after surgery, possibly due to the significant risk reduction of developing breast cancer. This might explain, why most women who underwent prophylactic mastectomy were satisfied with this decision, despite a perceived negative impact on body image, the intimate relationship and physical wellbeing.

Frontotemporal dementia in The Netherlands: patient characteristics and prevalence estimates from a population-based study.

Since 1994, a population-based study of frontotemporal dementia (FTD) in The Netherlands has aimed to ascertain all patients with FTD, and first prevalence estimates based on 74 patients were reported in 1998. Here, we present new prevalence estimates after expansion of our FTD population to 245 patients, with emphasis on the prevalence in the province Zuid-Holland where the main study centre is located. All neurologists and physicians in nursing homes received a yearly postal enquiry about suspected FTD cases. FTD was diagnosed in 245 patients according to the Lund-Manchester criteria, supported by neuroimaging and neuropsychology. tau mutation analysis was performed in a subgroup of 154 patients (63%), and 40 out of 98 patients (41%) who died during follow-up were autopsied during the course of the study. The prevalence of FTD in the province Zuid-Holland was 3.6 per 100,000 at age 50-59 years, 9.4 per 100,000 at age 60-69 years and 3.8 per 100,000 at age 70-79 years. The median age at onset of the 245 patients (51% female) was 58.0 years (range 33-80 years). Dementia in one or more first-degree family members was found in 43% of patients and mutation analysis of the tau gene showed mutations in 34 patients (19 P301L, five L315R, four G272V, four R406W, one Delta K280 and one S320F), all with a positive family history for dementia (14% of the total population, 32% of patients with a positive family history). Pathological findings in the 40 autopsied patients consisted of dementia lacking distinctive histology in 22%, FTD with ubiquitin-positive inclusions in 33%, Pick's disease in 15% and tauopathy in the remaining 30% of patients, with tau mutations identified in more than half of the latter patients. We conclude that the prevalence of FTD in The Netherlands is higher than previously reported, confirming that FTD is more common than was previously thought. The finding of tau mutations in 32% of patients with a positive family history for dementia justifies mutation screening in FTD patients with a positive family history, while tau mutations in non-familiar cases are rare.