Clinical and molecular characterization of a Brazilian cohort of campomelic dysplasia patients, and identification of seven new SOX9 mutations.

Campomelic dysplasia (CD) is an autosomal, dominantly inherited, skeletal abnormality belonging to the subgroup of bent bone dysplasias. In addition to bowed lower limbs, CD typically includes the following: disproportionate short stature, flat face, micrognathia, cleft palate, bell-shaped thorax, and club feet. Up to three quarters of 46, XY individuals may be sex-reversed. Radiological signs include scapular and pubic hypoplasia, narrow iliac wings, spaced ischia, and bowed femora and tibiae. Lethal CD is usually due to heterozygous mutations in SOX9, a major regulator of chondrocytic development. We present a detailed clinical and molecular characterization of nine Brazilian CD patients. Infants were either stillborn (n = 2) or died shortly after birth and presented similar phenotypes. Sex-reversal was observed in one of three chromosomally male patients. Sequencing of SOX9 revealed new heterozygous mutations in seven individuals. Six patients had mutations that resulted in premature transcriptional termination, while one infant had a single-nucleotide substitution at the conserved splice-site acceptor of intron 1. No clear genotype-phenotype correlations were observed. This study highlights the diversity of SOX9 mutations leading to lethal CD, and expands the group of known genetic alterations associated with this skeletal dysplasia.

Identification of a premature stop codon mutation in the PHGDH gene in severe Neu-Laxova syndrome-evidence for phenotypic variability.

In some cases Neu-Laxova syndrome (NLS) is linked to serine deficiency due to mutations in the phosphoglycerate dehydrogenase (PHGDH) gene. We describe the prenatal and postnatal findings in a fetus with one of the most severe NLS phenotypes described so far, caused by a homozygous nonsense mutation of PHGDH. Serial ultrasound (US) and pre- and postnatal magnetic resonance imaging (MRI) evaluations were performed. Prenatally, serial US evaluations suggested symmetric growth restriction, microcephaly, hypoplasia of the cerebellar vermis, micrognathia, hydrops, shortened limbs, arthrogryposis, and talipes equinovarus. The prenatal MRI confirmed these findings prompting a diagnosis of NLS. After birth, radiological imaging did not detect any gross bone abnormalities. DNA was extracted from fetal and parental peripheral blood, all coding exons of PHGDH were PCR-amplified and subjected to Sanger sequencing. Sequencing of PHGDH identified a homozygous premature stop codon mutation (c.1297C>T; p.Gln433*) in fetal DNA, both parents (first-cousins) being heterozygotes. Based on previous associations of mutations in this gene with a milder NLS phenotype, as well as cases of serine deficiency, these observations lend further support to a genotype-phenotype correlation between the degree of PHGDH inactivation and disease severity.

Microarray-based comparative genomic hybridization analysis in neonates with congenital anomalies: detection of chromosomal imbalances / Hibridização genômica comparativa baseada em microarranjos em neonatos com anomalias congênitas: detecção de desequilíbrios cromossômicos

OBJECTIVE: To identify chromosomal imbalances by whole-genome microarray-based comparative genomic hybridization (array-CGH) in DNA samples of neonates with congenital anomalies of unknown cause from a birth defects monitoring program at a public maternity hospital. METHODS: A blind genomic analysis was performed retrospectively in 35 stored DNA samples of neonates born between July of 2011 and December of 2012. All potential DNA copy number variations detected (CNVs) were matched with those reported in public genomic databases, and their clinical significance was evaluated. RESULTS: Out of a total of 35 samples tested, 13 genomic imbalances were detected in 12/35 cases (34.3%). In 4/35 cases (11.4%), chromosomal imbalances could be defined as pathogenic; in 5/35 (14.3%) cases, DNA CNVs of uncertain clinical significance were identified; and in 4/35 cases (11.4%), normal variants were detected. Among the four cases with results considered causally related to the clinical findings, two of the four (50%) showed causative alterations already associated with well-defined microdeletion syndromes. In two of the four samples (50%), the chromosomal imbalances found, although predicted as pathogenic, had not been previously associated with recognized clinical entities. CONCLUSIONS: Array-CGH analysis allowed for a higher rate of detection of chromosomal anomalies, and this determination is especially valuable in neonates with congenital anomalies of unknown etiology, or in cases in which karyotype results cannot be obtained. Moreover, although the interpretation of the results must be refined, this method is a robust and precise tool that can be used in the first-line investigation of congenital anomalies, and should be considered for prospective/retrospective analyses of DNA samples by birth defect monitoring programs. .

OBJETIVO: Identificar desequilíbrios cromossômicos por meio da hibridização genômica comparativa baseada em microarranjos (CGH-array) em amostras de DNA de neonatos com anomalias congênitas de causa desconhecida de um programa de monitoramento de defeitos congênitos em uma maternidade pública. MÉTODOS: Uma análise genômica cega foi realizada retrospectivamente em 35 amostras armazenadas de DNA de neonatos nascidos entre julho de 2011 e dezembro de 2012. Todas as possíveis variações no número de cópias (CNVs) de DNA foram comparadas com as relatadas em bases de dados genômicos públicas, e sua relevância clínica foi avaliada. RESULTADOS: De um total de 35 amostras testadas, foram detectados 13 desequilíbrios genômicos em 12/35 casos (34,3%). Em 4/35 casos (11,4%), os desequilíbrios cromossômicos poderiam ser definidos como patogênicos; em 5/35 (14,3%) deles foram identificadas CNVs de DNA de relevância clínica incerta; e, em 4/35 (11,4%), foram detectadas variações normais. Dentre os quatro casos com resultados considerados relacionados causalmente aos achados clínicos, 2/4 (50%) apresentaram alterações causais já relacionadas a síndromes de microdeleção bem definidas. Em 2/4 amostras (50%), os desequilíbrios cromossômicos encontrados, embora preditivos como patogênicos, não estavam relacionados anteriormente a entidades clínicas reconhecidas. CONCLUSÕES: A análise de CGH-array permitiu maior taxa de detecção de anomalias cromossômicas, e essa determinação é valiosa principalmente em neonatos com anomalias congênitas de etiologia desconhecida ou em casos em que os resultados do cariótipo não podem ser obtidos. Além disso, embora a interpretação dos resultados deva ser refinada, esse método é uma ferramenta robusta e precisa que pode ser usada na investigação de primeira linha de anomalias congênitas e deve ser considerada em análises futuras/retrospectivas de amostras de DNA por programas de monitoramento de defeitos congênitos. .

Microarray-based comparative genomic hybridization analysis in neonates with congenital anomalies: detection of chromosomal imbalances.

OBJECTIVE: To identify chromosomal imbalances by whole-genome microarray-based comparative genomic hybridization (array-CGH) in DNA samples of neonates with congenital anomalies of unknown cause from a birth defects monitoring program at a public maternity hospital. METHODS: A blind genomic analysis was performed retrospectively in 35 stored DNA samples of neonates born between July of 2011 and December of 2012. All potential DNA copy number variations detected (CNVs) were matched with those reported in public genomic databases, and their clinical significance was evaluated. RESULTS: Out of a total of 35 samples tested, 13 genomic imbalances were detected in 12/35 cases (34.3%). In 4/35 cases (11.4%), chromosomal imbalances could be defined as pathogenic; in 5/35 (14.3%) cases, DNA CNVs of uncertain clinical significance were identified; and in 4/35 cases (11.4%), normal variants were detected. Among the four cases with results considered causally related to the clinical findings, two of the four (50%) showed causative alterations already associated with well-defined microdeletion syndromes. In two of the four samples (50%), the chromosomal imbalances found, although predicted as pathogenic, had not been previously associated with recognized clinical entities. CONCLUSIONS: Array-CGH analysis allowed for a higher rate of detection of chromosomal anomalies, and this determination is especially valuable in neonates with congenital anomalies of unknown etiology, or in cases in which karyotype results cannot be obtained. Moreover, although the interpretation of the results must be refined, this method is a robust and precise tool that can be used in the first-line investigation of congenital anomalies, and should be considered for prospective/retrospective analyses of DNA samples by birth defect monitoring programs.

Recognition of the phenotype of thalidomide embryopathy in countries endemic for leprosy: new cases and review of the main dysmorphological findings.

Thalidomide is the best-known teratogen worldwide. It was first marketed as a sedative in the late 1950s, but the birth of ~10 000 children with birth defects resulted in the withdrawal of thalidomide from the market in 1962. Thalidomide embryopathy affects almost all organs but the main defects are concentrated in the limbs, eyes, ears, and heart. Shortly after the withdrawal of thalidomide from the market, its effectiveness in the treatment of erythema nodosum leprosum, an inflammatory condition resulting from leprosy, was reported and since the mid-1990s, the drug has been used widely in the treatment of cancers and autoimmune diseases, among other conditions. 40 000 new cases of leprosy are diagnosed every year in Brazil. Although there is a strict legislation for the prescription and use of thalidomide in Brazil, cases of thalidomide embryopathy have continued to be reported. Here, we present two new cases of thalidomide embryopathy identified in 2011 and review the major clinical findings in the literature that can aid the identification of the embryopathy.

Cardiac surgery unmasks latent hypoparathyroidism in a child with the 22q11.2 deletion syndrome.

The 22q11.2 deletion syndrome is a developmental field defect of the third and fourth pharyngeal pouches characterized by a spectrum of thymic and parathyroid gland abnormalities and conotruncal cardiac defects. Latent hypoparathyroidism, defined as normocalcaemia at rest but reduced ability to secrete parathyroid hormone (PTH) in response to pharmacologically evoked hypocalcaemia, is found in 30-50% of people with this syndrome. Its natural history is unknown. We describe a 1.5 year-old girl with tetralogy of Fallot, normal calcium metabolism and few facial dysmorphic features who developed transient hypoparathyroidism in the postoperative period, which lasted months and waxed and waned during this observation period. The clinical picture led us to the diagnosis of 22q11.2 deletion syndrome.

Beare-Stevenson syndrome: Two South American patients with FGFR2 analysis.

We report two patients with Beare-Stevenson syndrome. This syndrome presents craniosynostosis with or without clover-leaf skull, craniofacial anomalies, cutis gyrata, acanthosis nigricans, prominent umbilical stump, furrowed palms and soles, genital and anal anomalies. Both female newborn patients presented at birth with craniofacial anomalies, variable cutis gyrata in forehead and preauricular regions, prominent umbilical stump and anogenital anomalies. Furrowed palms and soles were also observed. The radiologic examination showed a cloverleaf-form craniosynostosis. Chromosomes were normal. They were born with respiratory distress and were connected to mechanical ventilation for ventilatory support. Both of them died in 50 days after birth due to secondary complications. The molecular analysis of these patients identified the mutation Tyr375Cys in the FGFR2 gene.