Diagnostic outcomes of 27 children referred by pediatricians to a genetics clinic in the Netherlands with suspicion of fetal alcohol spectrum disorders.

The characteristics of fetal alcohol spectrum disorders (FASD) constitute a specific facial phenotype, growth failure and neurodevelopmental defects. Reported FASD prevalences vary widely from 0.08 per 1,000 up to 68.0-89.2 per 1,000. We aimed to evaluate to which extent children referred with a suspicion of FASD, indeed have FASD. We included all 27 children referred to our genetic department with a suspicion of FASD between 2005 and 2010. Nineteen children (70.3%) were of non-Dutch ancestry, and 24 (88.9%) had been adopted. We used both the 4-Digit Code and the Revised Institute of Medicine criteria. More than half of the children did not meet either criteria for the diagnosis of FASD. Of note, after evaluation 8/27 children appeared not to have confirmed prenatal alcohol exposure. Two children referred for suspicion of FASD (neither of which were exposed to alcohol or met the criteria for FASD) had a pathogenic microstructural chromosomal rearrangement (del16p11.2 of 542 KB and dup1q44 of 915 KB). In 22/24 children (91.7%) there were other factors that may have affected their intellectual abilities, such as familial intellectual disability and social deprivation. We recommend a critical approach towards the diagnosis FASD, and to investigate all patients suspected to have FASD for other causative factors including genetic abnormalities.

Type IX collagen gene mutations can result in multiple epiphyseal dysplasia that is associated with osteochondritis dissecans and a mild myopathy.

Multiple epiphyseal dysplasia (MED) is a clinically variable and genetically heterogeneous disease that is characterized by mild short stature and early onset osteoarthritis. Autosomal dominant forms are caused by mutations in the genes that encode type IX collagen, cartilage oligomeric matrix protein, and matrilin-3: COL9A1, COL9A2, COL9A3, COMP, and MATN3, respectively. Splicing mutations have been identified in all three genes encoding type IX collagen and are restricted to specific exons encoding an equivalent region of the COL3 domain in all three alpha(IX) chains. MED has been associated with mild myopathy in some families, in particular one family with a COL9A3 mutation and two families with C-terminal COMP mutations. In this study we have identified COL9A2 mutations in two families with MED that also have osteochondritis dissecans and mild myopathy. This study therefore extends the range of gene-mutations that can cause MED-related myopathy. (c) 2010 Wiley-Liss, Inc.

Shprintzen-Goldberg syndrome associated with a novel missense mutation in TGFBR2.

Shprintzen-Goldberg syndrome (SGS) is a rare disorder characterized by a Marfan-like habitus, mental retardation and craniosynostosis. Cardiac abnormalities, such as aortic root dilation have also been noted as well as several skeletal abnormalities. Its nosological status is unclear as it is hard to delineate SGS from similar disorders, such as Furlong, Marfan type II, Camurati-Engelmann and Loeys-Dietz syndromes. It has been suggested that these conditions represent a phenotypical spectrum associated with aberrant TGF-beta signalling. In support of this notion, we found a novel TGFBR2 missense mutation in a patient with features of SGS.

Novel mutations in the BHD gene and absence of loss of heterozygosity in fibrofolliculomas of Birt-Hogg-Dubé patients.

Birt-Hogg-Dubé (BHD) syndrome is an autosomal-dominantly inherited cancer syndrome characterized by fibrofolliculomas, lung cysts leading to pneumothorax, and chromophobic/oncocytic renal cell carcinoma. The disease is caused by heterozygous mutations in the BHD gene encoding folliculin and all mutations reported putatively lead to protein truncation. Although the function of folliculin is unknown, it is thought to be a tumor suppressor, with loss of heterozygosity (LOH) initiating tumor formation. Here, we report on four novel BHD gene mutations, including two splice-site mutations, in patients presenting with skin lesions only. We further show that LOH cannot be detected in fibrofolliculomas from three patients, suggesting that for the manifestation of cutaneous tumors in BHD syndrome haplo-insufficiency of folliculin is sufficient to initiate uncontrolled growth. Renal microscopic oncocytosis in BHD is considered as a precursor to malignant kidney tumors and may likewise be the result of haplo-insufficiency, with somatic second-hit mutations or LOH giving rise to malignancy later in life.