Novel RAI1:c.2736delC Variant in Smith-Magenis Syndrome: Identification by Whole Genome Sequencing and Joint Analysis.

Smith-Magenis syndrome is a complex neurobehavioral genetic disorder with a broad phenotypic spectrum. While the etiology of SMS is commonly attributed to one-copy interstitial deletion in the 17p11.2 region (90-95% of cases), variants identified by sequence analysis in RAI1 have also been reported in 5-10% of cases. In this study, we report a 9-year-old male with global cognitive and psychomotor developmental delay, musculoskeletal and cardiovascular abnormalities, and dysmorphic craniofacial features. Joint analysis was performed on the whole-genome sequencing data obtained from the proband, unaffected parents, and unaffected brother. This quad analysis identified the novel de novo RAI1:c.2736delC variant. This is the first report of this variant in the literature. This report highlights the details of genome analysis and the patient's phenotypic spectrum.

Diagnosis of Two Unrelated Syndromes of Prader-Willi and Calpainopathy: Insight from Trio Whole Genome Analysis and Isodisomy Mapping.

PURPOSE: An investigation for the co-occurrence of two unrelated genetic disorders of muscular dystrophy and Prader-Willi syndrome (PWS) (OMIM#176270) using joint whole genome sequencing (WGS). METHODS: Trio WGS joint analysis was performed to investigate the genetic etiology in a proband with PWS, prolonged muscular hypotonia associated hyperCKemia, and early-onset obesity. The parents were unaffected. RESULTS: Results showed maternal isodisomy uniparental disomy (UPD) in chromosome 15, expanding from 15q11.2 to 15q22.2, including PWS regions at 15q11.2-15q13. Maternal heterodisomy was detected from 15q22.2 to 15q26.3. A pathogenic variant, NM_000070.3(CAPN3):c.550del (p.Thr184fs), was identified at 15q15.1 in a heterozygous state in the mother that was homozygous in the proband due to maternal isodisomy. CONCLUSION: This is the first study of the concurrent molecular etiology of PWS and calpainopathy (OMIM#253600) in the same patient. This report highlights the utility of joint analysis and the need for the assessment of autosomal recessive disease in regions of isodisomy in patients with complex and unexplained phenotypes.

GT microsatellite repeats in the heme oxygenase-1 gene promoter associated with abdominal aortic aneurysm in Croatian patients.

Abdominal aortic aneurysm (AAA) is a complex genetic disorder caused by the interplay of genetic and environmental risk factors. The number of (GT)(n) repeats in the heme oxygenase-1 (HO-1) gene promoter modulates transcription of this enzyme, which might have anti-inflammatory, antioxidant, antiapoptotic, and antiproliferative effect. The distribution of alleles and genotypes in Croatian individuals genotyped for the (GT)(n) HO-1 polymorphism was similar to that in other European populations. Frequency of the short (S) alleles (GT < 25) was higher in AAA patients (41.9%) than in non-AAA individuals (28.2%, p = 0.0026) because there were more SL heterozygotes among the AAA patients. The SL genotype appeared to increase the risk for AAA, but the increase was not statistically significant after adjustment for age, sex, smoking, hypertension, and hyperlipidemia (OR = 1.53, 95% CI 0.90-3.09, p = 0.062). These findings contradict those of the only other study performed so far on the association of (GT)(n) HO-1 polymorphism and AAA.

Pallister Killian syndrome: unusual significant postnatal overgrowth in a girl with otherwise typical presentation.

Pallister Killian syndrome (PKS) is a rare genetic disorder caused by tetrasomy of the short arm of chromosome 12, revealed usually in mosaic distribution of an extra i (12) (p10) chromosome in fibroblasts. The syndrome presents with a recognizable pattern of findings including pigmentary skin changes, coarse face, high forehead, sparse anterior scalp hair, hypertelorism, seizures and progressive psychomotor developmental delay. It was first described independently by Pallister in 1977 and by Killian and Teschler-Nikola in 1981. We report a case of 21 month old girl with PKS and significant overgrowth. Cytogenetic analysis was performed using the GTG banding technique. The karyotype of cultured lymphocytes was normal. The karyotype from skin fibroblasts was established as mosaic tetrasomy of 12p 47,XX,+i (12) (p10)/46,XX. The origin of the extra marker chromosome was determinated by fluorescence in situ hybridization with chromosome 12 specific DNA probes confirming that supernumerary marker is chromosome i (12p) in 68% of cells. Despite the excessive postnatal growth we found low serum growth hormone levels and reduced response to pharmacological stimulation test. This is also the first report of a postnatal patient in our country.

Association of 1166A>C AT1R, -1562C>T MMP-9, ACE I/D, and CCR5Δ32 Polymorphisms with Abdominal Aortic Aneurysm in Croatian Patients.

AIM: The purpose of this case-control study was to assess the association of abdominal aortic aneurysm (AAA) in Croatian patients with four genetic polymorphisms: SNP 1166A>C in the angiotensin II type 1 receptor gene (AT1R); SNP -1562C>T in the matrix metalloproteinase-9 gene (MMP-9); the deletion of 32 bp in the chemokine receptor 5 gene (CCR5); and the insertion/deletion (I/D) of 287 bp in the angiotensin-converting enzyme gene (ACE). METHODS: Case-control study conducted with 117 patients with confirmed AAA (AAA+) and 117 control subjects (AAA-). Genotyping was performed using PCR or PCR-RFLP analysis. Statistical analyses were performed using MedCalc 12.1 software. RESULTS: The deletion of 287 bp in the ACE gene (allele D) was more frequently found among AAA+ patients than AAA- subjects (66.7% vs. 47.9%, p = 0.0001), due principally to a higher percentage of DD homozygotes (46.2% vs. 15.4%, p < 0.0001). The associated increased risk for AAA was detected in both the nonadjusted recessive model of inheritance (odds ratio [OR] = 3.00, 95% confidence interval [CI] = 1.88-4.79, p = < 0.0001) and when adjusted for age, sex, smoking, hypertension, and hyperlipidemia (OR = 4.96; 95% CI = 1.68-14.59, p = 0.004). The adjusted recessive models also showed increased risk for AAA for the carriers of MMP-9 T allele (OR = 15.69, 95% CI = 1.40-175.41, p = 0.025). Patients with small aneurysms compared with those with large ones were more frequent carriers of the AT1R allele C (37.8% vs. 23.2%, p = 0.029), and logistic regression analysis showed decreased risk for developing large aneurysms in both adjusted models, dominant and recessive (OR = 0.3929, 95% CI = 0.1554-0.9932, p = 0.0483 and OR = 0.1728, 95% CI = 0.0331-0.9023; p = 0.0374, respectively). No difference among any type of the studied groups or subgroups was observed regarding the CCR5Δ32 polymorphism. CONCLUSIONS: ACE I/D is associated with AAA, and 1166A>C AT1R with the size of the aneurysm, while -1562C>T MMP-9 and CCR5Δ32 polymorphisms are most probably not associated with AAA in Croatian patients.