Novel KDM6A (UTX) mutations and a clinical and molecular review of the X-linked Kabuki syndrome (KS2)

We describe seven patients with KDM6A (located on Xp11.3 and encodes UTX) mutations, a rare cause of Kabuki syndrome (KS2, MIM 300867) and report, for the first time, germ-line missense and splice-site mutations in the gene. We demonstrate that less than 5% cases of Kabuki syndrome are due to KDM6A mutations. Our work shows that similar to the commoner Type 1 Kabuki syndrome (KS1, MIM 147920) caused by KMT2D (previously called MLL2) mutations, KS2 patients are characterized by hypotonia and feeding difficulties during infancy and poor postnatal growth and short stature. Unlike KS1, developmental delay and learning disability are generally moderate-severe in boys but mild-moderate in girls with KS2. Some girls may have a normal developmental profile. Speech and cognition tend to be more severely affected than motor development. Increased susceptibility to infections, join laxity, heart, dental and ophthalmological anomalies are common. Hypoglycaemia is more common in KS2 than in KS1. Facial dysmorphism with KDM6A mutations is variable and diagnosis on facial gestalt alone may be difficult in some patients. Hypertrichosis, long halluces and large central incisors may be useful clues to an underlying KDM6A mutation in some patients.

A three generation X-linked family with Kabuki syndrome phenotype and a frameshift mutation in KDM6A

Kabuki syndrome is a rare malformation syndrome characterized by a typical facial appearance, skeletal anomalies, cardiac malformation, and mild to moderate intellectual disability. In 55-80% of patients with Kabuki syndrome, a mutation in MLL2 is identified. Recently, eight patients with Kabuki syndrome and a mutation in KDM6A were described. In this report, we describe two brothers with a mutation in KDM6A inherited from their mother and maternal grandmother. The two boys have Kabuki-like phenotypes whereas the mother and grandmother present with attenuated phenotypes. This family represents the first instance of hereditary X-linked Kabuki syndrome. We present a short literature review of the patients described with a mutation in KDM6A.

Pilot study exploring lung allograft surfactant protein A (SP-A) expression in association with lung transplant outcome

Primary graft failure and chronic lung allograft dysfunction (CLAD) limit lung transplant long-term outcomes. Various lung diseases have been correlated with surfactant protein (SP) expression and polymorphisms. We sought to investigate the role of SP expression in lung allografts prior to implantation, in relation to posttransplant outcomes. The expression of SP-(A, B, C, D) mRNA was assayed in 42 allografts. Posttransplant assessments include pulmonary function tests, bronchoscopy, broncho-alveolar lavage fluid (BALF) and biopsies to determine allograft rejection. BALF was assayed for SP-A, SP-D in addition to cytokines IL-8, IL-12 and IL-2. The diagnosis of CLAD was evaluated 6 months after transplantation. Lung allografts with low SP-A mRNA expression prior to implantation reduced survival (Log-rank p < 0.0001). No association was noted for the other SPs. Allografts with low SP-A mRNA had greater IL-2 (p = 0.03) and IL-12 (p < 0.0001) in the BALF and a greater incidence of rejection episodes (p = 0.003). Levels of SP-A mRNA expression were associated with the SP-A2 polymorphisms (p = 0.015). Specifically, genotype 1A1A(0) was associated with lower SP-A mRNA expression (p < 0.05). Lung allografts with low levels of SP-A mRNA expression are associated with reduced survival. Lung allograft SP-A mRNA expression appears to be associated with SP-A gene polymorphisms.

Mutation spectrum in RAB3GAP1, RAB3GAP2, and RAB18 and genotype-phenotype correlations in warburg micro syndrome and Martsolf syndrome

Warburg Micro syndrome and Martsolf syndrome (MS) are heterogeneous autosomal-recessive developmental disorders characterized by brain, eye, and endocrine abnormalities. Causative biallelic germline mutations have been identified in RAB3GAP1, RAB3GAP2, or RAB18, each of which encode proteins involved in membrane trafficking. This report provides an up to date overview of all known disease variants identified in 29 previously published families and 52 new families. One-hundred and forty-four Micro and nine Martsolf families were investigated, identifying mutations in RAB3GAP1 in 41% of cases, mutations in RAB3GAP2 in 7% of cases, and mutations in RAB18 in 5% of cases. These are listed in Leiden Open source Variation Databases, which was created by us for all three genes. Genotype-phenotype correlations for these genes have now established that the clinical phenotypes in Micro syndrome and MS represent a phenotypic continuum related to the nature and severity of the mutations present in the disease genes, with more deleterious mutations causing Micro syndrome and milder mutations causing MS. RAB18 has not yet been linked to the RAB3 pathways, but mutations in all three genes cause an indistinguishable phenotype, making it likely that there is some overlap. There is considerable genetic heterogeneity for these disorders and further gene identification will help delineate these pathways.

Deletion of KDM6A, a histone demethylase interacting with MLL2, in three patients with Kabuki syndrome

Kabuki syndrome (KS) is a rare genetic disease that causes developmental delay and congenital anomalies. Since the identification of MLL2 mutations as the primary cause of KS, such mutations have been identified in 56%-76% of affected individuals, suggesting that there may be additional genes associated with KS. Here, we describe three KS individuals with de novo partial or complete deletions of an X chromosome gene, KDM6A, that encodes a histone demethylase that interacts with MLL2. Although KDM6A escapes X inactivation, we found a skewed X inactivation pattern, in which the deleted X chromosome was inactivated in the majority of the cells. This study identifies KDM6A mutations as another cause of KS and highlights the growing role of histone methylases and histone demethylases in multiple-congenital-anomaly and intellectual-disability syndromes.

Nonalcoholic fatty liver disease: an independent risk factor for colorectal neoplasia

BACKGROUND AND AIMS

Nonalcoholic fatty liver disease (NAFLD) is the hepatic manifestation of insulin resistance (IR), and IR is associated with an increased risk of colorectal carcinoma (CRC). Increased echogenicity suggesting NAFLD is a frequent incidental finding on ultrasound examination. We aimed to systematically evaluate whether NAFLD is an independent risk factor for colonic neoplasia.

PATIENTS AND METHODS

One thousand two hundred and eleven patients (603 males, 60.6 ± 9.6 years; 608 females, 61.1 ± 10.3 years) who underwent screening colonoscopy according to national screening recommendations for CRC were evaluated in a cross-sectional study. Colorectal adenomas were classified as tubular adenoma, advanced adenoma (villous features, size ≥ 1 cm or high-grade dysplasia) or carcinoma. NAFLD was diagnosed by increased echogenicity on ultrasound examination after serological exclusion of infectious, immunological, hereditary or alcoholic aetiology.

RESULTS

Nonalcoholic fatty liver disease was diagnosed in 367 (60.8%) males and in 265 (43.5%) females. The total rate of adenomas was increased in subjects with NAFLD (243/367 vs. 107/236 in males, P = 0.010; 94/265 vs. 78/343 in females; P = 0.014). In particular, more tubular adenomas (127/367 vs. 56/236; P = 0.006), adenomas of the rectum (40/367 vs. 8/236; P = 0.004) and more cancers (6/367 vs. 1/236; P < 0.001) were observed in males with NAFLD. In females with NAFLD, more tubular adenomas (59/265 vs. 48/343; P = 0.011) and adenomas of the proximal colon (51/265 vs. 40/343; P = 0.041) were observed. Multivariate regression analyses demonstrated an independent association of colorectal adenomas with hepatic steatosis after adjustment for age, sex, body mass index and glucose intolerance (OR 1.47; 95% CI 1.079-2.003; P = 0.015).

CONCLUSION

Patients with NAFLD undergoing screening colonoscopy reveal significantly more CRC precursor lesions and early CRC compared with subjects without NAFLD. This elevated risk is independent from other manifestations of IR. These findings suggest that detecting fatty liver on ultrasound should heighten the awareness for referral to screening colonoscopy.

Relationship between cytokine levels and coronary artery disease in women

Inflammation is thought to have a role in the pathogenesis of atherosclerotic coronary artery disease (CAD), and the measurement of markers of inflammation has been suggested to improve the identification of individuals at risk for this disease. The incidence of CAD in women is not accounted for by conventional risk factors, and the association of CAD and the antiinflammatory cytokine transforming growth factor beta1 (TGF-beta1) in this population is unknown. Associations among TGF-beta1, the inflammatory cytokine tumor necrosis factor alpha (TNF-alpha), and CAD severity in inner city women were examined. Fifty-three women requiring angiography (mean age, 60.7 years) were stratified as having on of the following conditions: 0 vessel disease (VD) (n = 20), 1 (VD) (n = 10), 2 VD (n = 9), or 3 VD (n = 14). Fasting serum cytokine levels were determined by enzyme-linked immunosorbent assay. Serum TGF-beta1 was lower in patients with extensive disease (2 and 3 VD versus 0 and 1 VD). The lowest TGF-beta1 levels (<30 ng/mL) were in the 2 and 3 VD groups. In contrast, in the 0 and 1 VD groups, TGF-beta1 was above 41 ng/mL. Serum TGF-beta1 correctly classified the severity of CAD in 62.3% of patients, with a predictive threshold of 58 ng/mL by discriminant function analysis. TGF-beta1 may be a determinant of clinical events and outcome in CAD in women.

Quantitation of latent varicella-zoster virus DNA in human trigeminal ganglia by polymerase chain reaction

Competitive polymerase chain reaction was used to quantitate latent varicella-zoster virus (VZV) DNA in human trigeminal ganglia. Ganglionic DNA from five subjects was amplified with oligonucleotide primers specific for VZV gene 28. Two of the samples were also analyzed with primers specific for VZV gene 62. Our results indicated that there are 6 to 31 copies of the VZV genome in every 100,000 ganglionic cells.