Neonatal-Onset Congenital Ectropion Uveae May Be Caused by a Distinct CYP1B1 Pathologic Variant.

PURPOSE: To report underlying genetic variants of recently described distinct phenotype of newborn glaucoma: neonatal-onset congenital ectropion uveae (NO-CEU). DESIGN: Prospective cohort study. METHODS: Setting: tertiary care teaching institute. SUBJECTS: Thirteen children with clinical diagnosis of NO-CEU who had completed 1-year follow-up after glaucoma surgery and had undergone clinical exome sequencing (CES) by selective capture and sequencing of the protein-coding regions of the genes including 19 candidate genes for NO-CEU were assessed. The same criteria were applied for evaluating pathogenicity of variants to all the candidate genes. OUTCOME MEASURES: primary-genetic variants found on CES keeping in view the clinical indication of congenital glaucoma; secondary-corneal clarity and intraocular pressure (IOP) at baseline and 1-year follow-up, interventions required to control IOP, and postoperative visual acuity. The genetic variants were correlated with the outcome. RESULTS: All 13 patients diagnosed with NO-CEU had onset of glaucoma at birth and severe bilateral disease. Twelve of 13 (92.3%) patients harbored CYP1B1 variants. Nine of these 12 patients (83.3%) were homozygous for [c.1169G>A(p.Arg390His)] in exon-3 of CYP1B, with 5 common homozygous single-nucleotide polymorphisms flanking the pathogenic variant. They had intractable glaucoma and required multiple surgeries. Six patients had persistent corneal opacities, necessitating optical iridectomies. Three patients were compound heterozygous for CYP1B1 variants, showing [c.1169G>A(p.Arg390His)] along with [c.1103G>A(p.Arg368His)], [c.1103G>A (p.Arg368His)] along with [c.1403_1429dup(p.Arg468_Ser476dup)], and [(c.1063C>T(p.Arg355Ter)] along with [c.1325del(p.Pro442GlnfsTer15)]. These patients had better visual outcomes. CONCLUSIONS: NO-CEU appears to be a phenotypic marker for specific CYP1B1 genotypes, one of which is [c.1169G>A(p.Arg390His)] in our study population. Phenotype recognition is helpful to characterize the underlying genetic variants.

Meta-analysis of CYP1B1 gene mutations in primary congenital glaucoma patients.

Primary congenital glaucoma (PCG) is a rare and severe form of glaucoma and is usually transmitted as an autosomal-recessive disease. However, PCG is more common in certain ethnic and geographic groups where consanguineous relationships are common. The importance of this review is to inspect the mutations in the cytochrome P450 1B1 gene (CYP1B1) and to highlight the interest of the genetic study of CYP1B1 mutations. An in-depth study was carried out by the following search engines: PubMed, Scopus, clinic key and direct science for articles that have been published from 2011 until 2020. One hundred and sixty-one mutations were found in 1641 tested patients and three families, including 78 novel mutations. We identified a no significant difference in the sex ratio and the bilaterality was reported in the majority of patients. We have shown through this study that inbreeding plays an important role in the pathogenesis of PCG transmission compared to the sporadic mutations that have been found in some cases. The majority of the included studies were from ASIA (64.3%), followed by Europe (17.85%), America (10.71%) and Africa (7.14%). The first and most common mutation in our study is 182 G>A (p.Gly61Glu). It was identified in Iran, Portugal and Saudi Arabia and for the first time in Brazil and Vietnam. The greatest number of mutations in common is p.Gly61Glu. Mainly within five countries: Iran, Portugal, Saudi Arabia, Brazil and Vietnam. The first step in PCG screening should be a genetic test looking for founder and common mutation coupled with a clinical examination.

SVEP1 as a Genetic Modifier of TEK-Related Primary Congenital Glaucoma.

Purpose: Affecting children by age 3, primary congenital glaucoma (PCG) can cause debilitating vision loss by the developmental impairment of aqueous drainage resulting in high intraocular pressure (IOP), globe enlargement, and optic neuropathy. TEK haploinsufficiency accounts for 5% of PCG in diverse populations, with low penetrance explained by variable dysgenesis of Schlemm's canal (SC) in mice. We report eight families with TEK-related PCG, and provide evidence for SVEP1 as a disease modifier in family 8 with a higher penetrance and severity. Methods: Exome sequencing identified coding/splice site variants with an allele frequency less than 0.0001 (gnomAD). TEK variant effects were assayed in construct-transfected HEK293 cells via detection of autophosphorylated (active) TEK protein. An enucleated eye from an affected member of family 8 was examined via histology. SVEP1 expression in developing outflow tissues was detected by immunofluorescent staining of 7-day mouse anterior segments. SVEP1 stimulation of TEK expression in human umbilical vascular endothelial cells (HUVECs) was measured by TaqMan quantitative PCR. Results: Heterozygous TEK loss-of-function alleles were identified in eight PCG families, with parent-child disease transmission observed in two pedigrees. Family 8 exhibited greater disease penetrance and severity, histology revealed absence of SC in one eye, and SVEP1:p.R997C was identified in four of the five affected individuals. During SC development, SVEP1 is secreted by surrounding tissues. SVEP1:p.R997C abrogates stimulation of TEK expression by HUVECs. Conclusions: We provide further evidence for PCG caused by TEK haploinsufficiency, affirm autosomal dominant inheritance in two pedigrees, and propose SVEP1 as a modifier of TEK expression during SC development, affecting disease penetrance and severity.

Biallelic CPAMD8 Variants Are a Frequent Cause of Childhood and Juvenile Open-Angle Glaucoma.

PURPOSE: Developmental abnormalities of the ocular anterior segment in some cases can lead to ocular hypertension and glaucoma. CPAMD8 is a gene of unknown function recently associated with ocular anterior segment dysgenesis, myopia, and ectopia lentis. We sought to assess the contribution of biallelic CPAMD8 variants to childhood and juvenile open-angle glaucoma. DESIGN: Retrospective, multicenter case series. PARTICIPANTS: A total of 268 probands and their relatives with a diagnosis of childhood or juvenile open-angle glaucoma. PURPOSE: Developmental abnormalities of the ocular anterior segment in some cases can lead to ocular hypertension and glaucoma. CPAMD8 is a gene of unknown function recently associated with ocular anterior segment dysgenesis, myopia, and ectopia lentis. We sought to assess the contribution of biallelic CPAMD8 variants to childhood and juvenile open-angle glaucoma. METHODS: Patients underwent a comprehensive ophthalmic assessment, with DNA from patients and their relatives subjected to genome, exome, or capillary sequencing. CPAMD8 RNA expression analysis was performed on tissues dissected from cadaveric human eyes. MAIN OUTCOME MEASURES: Diagnostic yield within a cohort of childhood and juvenile open-angle glaucoma, prevalence and risk of ophthalmic phenotypes, and relative expression of CPAMD8 in the human eye. RESULTS: We identified rare (allele frequency < 4×10-5) biallelic CPAMD8 variants in 5.7% (5/88) of probands with childhood glaucoma and 2.1% (2/96) of probands with juvenile open-angle glaucoma. When including family members, we identified 11 individuals with biallelic variants in CPAMD8 from 7 unrelated families. Nine of these individuals were diagnosed with glaucoma (9/11, 81.8%), with a mean age at diagnosis of 9.22±14.89 years, and all individuals with glaucoma required 1 or more incisional procedures to control high intraocular pressure. Iris abnormalities were observed in 9 of 11 individuals, cataract was observed in 8 of 11 individuals (72.7%), and retinal detachment was observed in 3 of 11 individuals (27.3%). CPAMD8 expression was highest in neural crest-derived tissues of the adult anterior segment, suggesting that CPAMD8 variation may cause malformation or obstruction of key drainage structures. CONCLUSIONS: Biallelic CPAMD8 variation was associated with a highly heterogeneous phenotype and in our cohorts was the second most common inherited cause of childhood glaucoma after CYP1B1 and juvenile open-angle glaucoma after MYOC. CPAMD8 sequencing should be considered in the investigation of both childhood and juvenile open-angle glaucoma, particularly when associated with iris abnormalities, cataract, or retinal detachment.

Cataract extraction in patients with primary congenital glaucoma.

OBJECTIVE: To assess incidence and risk factors of cataract extraction in patients with primary congenital glaucoma, surgical outcome, and complications. MATERIAL AND METHOD: Retrospective cohort study, in which 108 patients with primary congenital glaucoma were included. Data collected were need for cataract extraction and at what age, intraocular pressure at diagnosis of primary congenital glaucoma, required antiglaucomatous surgeries, possible mutation in the CYP1B1 gene, and final visual acuity. Among the patients who required cataract extraction were visual acuity, intraocular pressure, and complications, evaluated preoperatively and postoperatively. The data were analysed with STATA. RESULTS: A total of 198 eyes of 108 patients were included, with a median follow-up of 8 years (range: 5-53). In all, 32 eyes (16.2%) of 24 patients (22%) required cataract extraction. The median age for cataract extraction was 12.94 years (interquartile range: 2.42-22). The main identified risk factors associated with cataract extraction were antiglaucomatous surgeries (hazard ratio 1.48, p < 0.001) and valvular implant (hazard ratio 2.78, p < 0.001). Lens was implanted in 30/32 eyes and the main complications were intraocular pressure decontrol (n = 13), capsular fibrosis (n = 7), corneal decompensation (n = 4), lens subluxation (n = 4), and endophthalmitis (n = 1). Visual acuity improvement was observed after cataract extraction in 66.67% of eyes. CONCLUSIONS: There is a high incidence of cataract surgery in patients with primary congenital glaucoma, but generally outside of pediatric age. A greater risk of cataract extraction was identified in those patients with a greater number of antiglaucomatous surgeries, especially after valvular implantation. Despite the high rate of complications related to cataract extraction in primary congenital glaucoma, good visual improvement was observed after surgery.

A Rare Case Report of Frank Ter Haar Syndrome in a Sibling Pair Presenting With Congenital Glaucoma.

Frank Ter Haar syndrome (FTHS) is a rare autosomal recessive disorder with characteristic skeletal, cardiac, ocular, and craniofacial abnormalities. We report a sibling pair presenting with clinical features typical of FTHS, born to consanguineous parents, with a novel mutation in the SH3PXD2B gene on chromosome 5q35.1 that results in premature truncation of the protein encoded. The children presented with brachycephaly, multiple joint contractures, cardiac valvular defects, bilateral megalocornea, and congenital glaucoma. Trabeculotomy combined with trabeculectomy was performed in both siblings to control intraocular pressure. The characteristic clinical features with the underlying genetic defects confirmed the diagnosis of FTHS. Early diagnosis and treatment of congenital glaucoma preserved vision in the children.

Childhood glaucoma genes and phenotypes: Focus on FOXC1 mutations causing anterior segment dysgenesis and hearing loss.

Childhood glaucoma is an important cause of blindness world-wide. Eleven genes are currently known to cause inherited forms of glaucoma with onset before age 20. While all the early-onset glaucoma genes cause severe disease, considerable phenotypic variability is observed among mutations carriers. In particular, FOXC1 genetic variants are associated with a broad range of phenotypes including multiple forms of glaucoma and also systemic abnormalities, especially hearing loss. FOXC1 is a member of the forkhead family of transcription factors and is involved in neural crest development necessary for formation of anterior eye structures and also pharyngeal arches that form the middle ear bones. In this study we review the clinical phenotypes reported for known FOXC1 mutations and show that mutations in patients with reported ocular anterior segment abnormalities and hearing loss primarily disrupt the critically important forkhead domain. These results suggest that optimal care for patients affected with anterior segment dysgenesis should include screening for FOXC1 mutations and also testing for hearing loss.

CYP1B1 Gene and Phenotypic Correlation in Patients From Northeastern Brazil With Primary Congenital Glaucoma.

PURPOSE: To identify variants in the CYP1B1 gene in northeastern Brazilian patients with primary congenital glaucoma (PCG) and possible genotype-phenotype correlations. MATERIALS AND METHODS: This is a cross-sectional observational study of 17 nonrelated patients with PCG, performed at the Altino Ventura Foundation, Recife, Brazil, between December 2017 and February 2018. All patients underwent an examination, including gathering information from their medical records, slit-lamp examination, fundoscopy, tonography, and measuring corneal diameter and thickness. RESULTS: The mean age at the time of the examination was 27.7 years; 52.9% (n=9) were male, 29.4% (n=5) had history of parental consanguinity. The mean age when the diagnosis was confirmed was 0.53±2.18 years. Horizontal corneal diameter ranged from 12 to 16 mm (mean: 14.05±1.42 mm) and the IOP mean value was 17.31±9.84 mm Hg. Predicted pathogenic variants of the CYP1B1 gene were identified in 4 patients (23.5%). The differences among all clinical parameters did not reach statistical significance between individuals with and without CYP1B1 variants (P-values >0.05). CONCLUSIONS: Two variants which had not been previously related to PCG in Brazil (c.182G>A, c.241T>A) were identified. No statistically significant genotype-phenotype correlations were found.

Update in Genetics and Surgical Management of Primary Congenital Glaucoma

Primary congenital glaucoma (PCG) continues to be an important cause of visual impairment in children despite advances in medical and surgical treatment options. The progressive and blinding nature of the disease, together with the long lifespan of the affected population, necessitates a thorough understanding of the pathophysiology of PCG and the development of long-lasting treatment options. The first part of this review discusses the genetic features and makeup of this disorder, including all currently identified genetic loci (GLC3A, GLC3B, GLC3C and GLC3D) and relevant protein targets important for trabecular and Schlemm canal dysgenesis. These target molecules primarily include CYP1B1, LTBP2, and TEK/Tie2 proteins. Their potential roles in PCG pathogenesis are discussed with the purpose of bringing the readers up to date on the molecular genetics aspect of this disorder. Special emphasis is placed on functional implications of reported genetic mutations in the setting of PCG. The second part of the review focuses on various modifications and refinements to the traditional surgical approaches performed to treat PCG, including advances in goniotomy and trabeculotomy ab externo techniques, glaucoma drainage implant surgery and cyclodiode photocoagulation techniques that ultimately provide safer surgical approaches and more effective intraocular pressure control in the 21st century.

Achondroplasia With Congenital Onset Glaucoma, and Presumed Axenfeld-Rieger Anomaly.

We report the first case to our knowledge of a 1-week-old female infant with familial inherited achondroplasia associated with bilateral congenital onset glaucoma, posterior embryotoxon and iris hypoplasia suggestive of ocular Axenfeld-Rieger anomaly.

Analysis of CYP1B1 in pediatric and adult glaucoma and other ocular phenotypes.

PURPOSE: The CYP1B1 gene encodes an enzyme that is a member of the cytochrome P450 superfamily. Mutations in CYP1B1 have been mainly reported in recessive pediatric ocular phenotypes, such as primary congenital glaucoma (PCG) and congenital glaucoma with anterior segment dysgenesis (CG with ASD), with some likely pathogenic variants also identified in families affected with adult-onset primary open angle glaucoma (POAG). METHODS: We examined CYP1B1 in 158 pediatric patients affected with PCG (eight), CG with ASD (22), CG with other developmental ocular disorders (11), juvenile glaucoma with or without additional ocular anomalies (26), and ASD or other developmental ocular conditions without glaucoma (91); in addition, a large cohort of adult patients with POAG (193) and POAG-negative controls (288) was examined. RESULTS: Recessive pathogenic variants in CYP1B1 were identified in two PCG pedigrees, three cases with CG and ASD, and two families with CG and other ocular defects, such as sclerocornea in one patient and microphthalmia in another individual; neither sclerocornea nor microphthalmia has been previously associated with CYP1B1. Most of the identified causative mutations are new occurrences of previously reported pathogenic alleles with two novel variants identified: a c.1325delC, p.(Pro442Glnfs*15) frameshift allele in a family with PCG and a c.157G>A, p.(Gly53Ser) variant identified in a proband with CG, Peters anomaly, and microphthalmia. Analysis of the family history in the CYP1B1-positive families revealed POAG in confirmed or presumed heterozygous relatives in one family with PCG and two families with ASD/CG; POAG was associated with the c.1064_1076del, p.(Arg355Hisfs*69) allele in two of these pedigrees. Screening of an unrelated POAG cohort identified the same c.1064_1076del heterozygous allele in one individual with sporadic POAG but not in age- and ethnicity-matched POAG-negative individuals. Overall, there was no significant enrichment for mutant alleles in CYP1B1 within the POAG cases compared to the controls. CONCLUSIONS: In summary, these data expand the mutational and phenotypic spectra of CYP1B1 to include two novel alleles and additional developmental ocular phenotypes. The contribution of CYP1B1 to POAG is less clear, but loss-of-function variants in CYP1B1, especially c.1064_1076del, p.(Arg355Hisfs*69), may be associated with an increased risk for POAG.

Screening of the LTBP2 gene in 214 Chinese sporadic CYP1B1-negative patients with primary congenital glaucoma.

PURPOSE: To identify deleterious mutations in the latent transforming growth factor-ß-binding protein 2 (LTBP2) gene in sporadic patients with primary congenital glaucoma (PCG) from a Han Chinese population, which had been excluded for mutations in the CYP1B1 gene. METHODS: In this retrospective case-control study, 36 coding exons and adjacent exon-intron boundaries of LTBP2 were amplified with PCR and screened for mutations with Sanger sequencing in DNA samples of 214 sporadic patients with PCG. Sequence variants identified in the patients with PCG were subsequently screened in 100 unaffected control subjects and the unaffected parents of the patients with PCG who had sequence changes in LTBP2. RESULTS: Eight heterozygous single nucleotide polymorphisms (SNPs) in coding regions of LTBP2 were identified in the patients with PCG. Four of these SNPs were missense changes that resulted in the replacement of amino acids (rs2304707, rs116914994, rs45468895, and rs763035721), two of which (rs2304707 and rs116914994) were also present in the control subjects. No significant differences in the frequencies of the missense SNPs were found between the patients with PCG and the controls. The two missense SNPs, rs45468895 and rs763035721, which were each found in one patient also existed in their unaffected parents, suggesting that these two SNPs were not segregated in these families and are unlikely to be a disease-causative variant. In addition, four synonymous SNPs were detected in the patients with PCG (rs61738025, rs862031, rs199805158, and rs12586758). CONCLUSIONS: The results showed that no deleterious mutations were found in coding regions of LTBP2 in patients with PCG, suggesting that it is not a causal gene for PCG in the Han Chinese population.

Functional characterization of eight rare missense CYP1B1 variants involved in congenital glaucoma and their association with null genotypes.

PURPOSE: To evaluate the function of eight missense CYP1B1 single nucleotide variants (SNVs) previously identified in patients with primary congenital glaucoma (PCG). METHODS: The eight variants were obtained by site-directed mutagenesis and transiently expressed in human embryonic kidney 293-T (HEK-293T) cells. The catalytic activity, protein stability and subcellular localization of the different recombinant CYP1B1 variants were assessed in this cell line. RESULTS: Six of the mutant CYP1B1 proteins (p.L89P, p.A106D, p.R390S, p.P437L, p.C470Y and S485F) showed catalytic activity values ranging from 0% to 4% of those of the wild-type protein and were considered null variants. The activity values of the two remaining variants (p.F123L and p.A237E) were close to 20% of that of the wild-type enzyme and were classified as hypomorphic variants. Reduced protein stability contributed partially to the decreased catalytic activity of two of the mutant enzymes (p.L89P and p.A106D). None of the CYP1B1 variants showed intracellular aggregation and they all displayed a normal subcellular localization in the endoplasmic reticulum, suggesting that they had folded into a wild-type-like structure. The enzymatic activity associated with the different genotypes in which these CYP1B1 variants were present was estimated to range from 0% to 10% of that of the wild-type genotype. CONCLUSION: These results confirm the pathogenicity of the analysed missense CYP1B1 variants and further support the concept that either absent or very low CYP1B1 activity levels are the primary molecular defect involved in PCG pathogenesis.

CYP1B1 and MYOC Mutations in Vietnamese Primary Congenital Glaucoma Patients.

PURPOSE: Primary congenital glaucoma (PCG, OMIM 231300), the most common glaucoma in infancy, is caused by developmental defects in the anterior chamber angle. The 3 implicated genes are cytochrome P450 family I subfamily B polypeptide 1 (CYP1B1), latent transforming growth factor ß-binding protein 2 (LTBP2), and myocilin (MYOC). In this study, we sought to determine CYP1B1 and MYOC sequence variations in a Vietnamese cohort of index cases with PCG and their families. METHODS: Thirty Vietnamese subjects with PCG and 120 normal Vietnamese subjects were recruited. PCG was defined by the presence of at least 2 of the following clinical manifestations: increased corneal diameter (>10 mm at birth), corneal edema, Haab's striae, optic disc changes, and absence of other ocular or systemic diseases associated with childhood glaucoma. The coding exons, intron and exon boundaries, and untranslated regions of CYP1B1 and MYOC genes were PCR amplified and subjected to bidirectional sequencing in all subjects. RESULTS: We identified 2 homozygous and 3 heterozygous CYP1B1 sequence alterations in our study subjects. Among the 5 mutations identified, 2 (p.H279L and p.L283F) were novel mutations, whereas 3 (p.A121_S122insDRPAFA, p.L107V, and p.V320L) had been previously reported in PCG cases. None of these mutations was observed in any of the 120 controls. Haplotypes generated with 6 non-disease-causing intragenic single nucleotide polymorphisms detected in CYP1B1 indicated that the most common haplotype in Vietnamese population is similar to that found in Chinese and Japanese. The genotype-phenotype correlation showed no significant difference between mutation and no-mutation groups for quantitative clinical features (presenting intraocular pressure, corneal diameter, number of surgeries performed, the cup-to-disc ratio) as well as for qualitative factors (bilateral cases, phenotype severity, and the prognosis) (P>0.05). CONCLUSIONS: Five out of 30 families with PCG (16.7%) had disease attributable to CYP1B1 alterations suggesting that CYP1B1 is not the major gene causing PCG in Vietnamese unlike in the case of Arab or Romany patients. This percentage is similar to that detected in studies of Japanese and Chinese patients with sporadic PCG. PCG has proven to be an ocular disease of genetic heterogeneity, calling for further studies to identify novel genes causing this disease.

Phenotype and Genotype Correlation in Iranian Primary Congenital Glaucoma Patients.

PURPOSE: To explore the correlation between clinical manifestations of primary congenital glaucoma (PCG) and CYP1B1 mutations. METHODS: A clinical and molecular genetic study was performed on a cohort of 17 patients with PCG and known CYP1B1 mutation profile including 10 subjects with and 7 cases without mutations. Ophthalmolgical records were reviewed and phenotype which was defined by age at onset, presenting intraocular pressure (IOP), corneal diameter, and vertical cup to disc ratio, and the number of procedures was correlated with the presence or absence of CYP1B1 mutations. RESULTS: Overall, 8 mutations were identified in 10 patients. The disease became manifest earlier than 1 month of age in 9 of 10 (90%) cases with, as compared with 2 of 7 (28.6%) patients without mutations (P=0.035). Baseline IOP was 29.3±6.5 mm Hg in the mutation-positive group versus 17.6±3.7 mm Hg in subjects without mutations (P<0.001). Patients with mutations also had significantly higher IOP throughout follow-up (P<0.002). The number of operations was significantly higher in subjects with mutations (3.3±1.8 vs. 1.8±1.5 procedures, P=0.025). Six patients (60%) with mutations were female as compared with 1 subject (14.3%) in the nonmutation group (P=0.134). There was no significant difference between the study groups in terms of corneal diameter (P=0.475) and vertical cup to disc ratio (P=0.794). CONCLUSIONS: PCG patients with CYP1B1 mutations seem to have earlier onset disease, display more severe manifestations, and require more operations as compared with subjects without such mutations. These findings may have implications in prognosticating the disease and genetic counseling.

Molecular Karyotyping of a Dysmorphic Girl from Saudi Arabia with CYP1B1-negative Primary Congenital Glaucoma.

PURPOSE: To report the results of molecular karyotyping for a dysmorphic girl with CYP1B1-negative primary congenital glaucoma from Saudi Arabia, where CYPB1 mutations account for over 90% of cases of primary congenital glaucoma and the remaining cases are idiopathic. METHODS: CYP1B1 sequencing in the affected child; high-resolution array comparative genomic hybridization (array CGH) of the affected child and both unaffected parents (Affymetrix Cytogenetics Whole-Genome 2.7M array; Affymetrix Inc., Santa Clara, CA, USA). RESULTS: The girl did not harbor CYP1B1 mutation by Sanger sequencing. Array CGH revealed 2 de novo 7p heterozygous duplications (7p21 - 7p14, encompassing 223 genes, and 7p14-7p11.2, encompassing 225 genes) and a 4p homozygous microdeletion (4p14) encompassing one gene only, DTHD1. CONCLUSIONS: The fact that this dysmorphic girl is Saudi Arabian and has CYP1B1-negative primary congenital glaucoma suggests that her glaucoma phenotype is related to her de novo copy number variation. Loss or gain of one or more of the genes encompassed in the identified chromosomal areas may be associated with primary congenital glaucoma and/or other observed phenotypic features.

The Role of Genetic Ancestry in Brazilian Patients With Primary Congenital Glaucoma.

PURPOSE: The relationship between clinical data and genetic ancestry in Brazilian patients with primary congenital glaucoma (PCG) was studied. PATIENTS AND METHODS: Thirty patients with PCG and 60 unrelated controls underwent a complete ophthalmological examination. The PCG inclusion criterion was prior surgery with a minimum follow-up of 6 months after the last surgical procedure. Clinical data were recorded and DNA from each individual was extracted and genotyped for a panel of 40 validated ancestry-informative insertion-deletion DNA polymorphisms (indels). RESULTS: Eighteen (60%) children had bilateral disease and 16 (53.3%) were male. The mean age at diagnosis was 6.3 months and surgical follow-up time varied from 8 to 85 months. For the PCG group, the proportion of Europeans, Africans, and Amerindians was 0.784±0.044 (mean±SEM), 0.149±0.035, and 0.067±0.023, respectively, whereas for the control group was 0.730±0.048, 0.132±0.034, and 0.138±0.032, respectively. An increased proportion of African indels was associated with worse surgical prognosis (P=0.036). There was also a statistically significant (P<0.05) positive correlation between axial length and African component (initial: R=0.625; final: R=0.567). CONCLUSIONS: An increased proportion of African indels was associated with worse prognosis for PCG in a mixed population. Genetic ancestry markers may be helpful in assessing risk factors for surgical outcomes in PCG. Further studies are needed to unveil the role of ancestry in heterogeneous populations such as Brazilians with PCG.

CYP1B1 gene analysis and phenotypic correlation in Portuguese children with primary congenital glaucoma.

PURPOSE: To investigate the prevalence of CYP1B1 mutations in Portuguese children with primary congenital glaucoma (PCG) and to study the possible correlations between the mutation status and clinical features of the disease. METHODS: DNA sequencing analysis of the CYP1B1 gene was used to screen 21 children with PCG followed on Paediatric Ophthalmology and Medical Genetics consultations at D. Estefânia's Hospital (Centro Hospitalar de Lisboa Central, Portugal). The effect of mutations on the phenotype of the patients was also assessed. Presence and type of mutations in CYP1B1 gene, age at diagnosis, bilaterality, age at first surgery, postoperative intraocular pressure and corneal diameter, final visual acuity, number of surgical reinterventions, and number of antiglaucoma medications required postoperatively were noted. RESULTS: Mutations in the CYP1B1 gene in 6 patients (28.57%) were detected, all compound heterozygotes. Seven types of mutations were identified: c.182G>A, c.317C>A, c.535delG, c.1064_1076del, c.1159G>A, c.1310C>T, and c.1390dupT. All patients with these mutations developed bilateral PCG, whereas in the group without mutations only 7 (46.67%) showed bilateral disease. Age at diagnosis was lower in the group of patients with these mutations (0.0 ± 0.00 vs 4.5 ± 2.63 months, p<0.01). In the remaining variables (age at first surgery, postoperative intraocular pressure and corneal diameter, final visual acuity, number of surgical reinterventions and antiglaucoma medications required postoperatively), no significant differences between the groups were detected (p>0.05 for all comparisons). CONCLUSIONS: This study is the first to report the variety of mutations in the CYP1B1 gene in a group of Portuguese children with PCG and to describe 2 new mutations. Genetic analysis of PCG must be carried out, although it has not yet been possible to establish a genotype-phenotype correlation, with the exception of bilaterality and early age at diagnosis.