An exceptional Albanian family with seven children presenting with dysmorphic features and mental retardation: maternal phenylketonuria.
ABSTRACT: BACKGROUND: Phenylketonuria is an inborn error of amino acid metabolism which can cause severe damage to the patient or, in the case of maternal phenylketonuria, to the foetus. The maternal phenylketonuria syndrome is caused by high blood phenylalanine concentrations during pregnancy and presents with serious foetal anomalies, especially congenital heart disease, microcephaly and mental retardation. CASE PRESENTATION: We report on an affected Albanian woman and her seven children. The mother is affected by phenylketonuria and is a compound heterozygote for two pathogenetic mutations, L48S and P281L. The diagnosis was only made in the context of her children, all of whom have at least one severe organic malformation. The first child, 17 years old, has a double-chambered right ventricle, vertebral malformations and epilepsy. She is also mentally retarded, microcephalic, exhibits facial dysmorphies and small stature. The second child, a girl 15 years of age, has severe mental retardation with microcephaly, small stature and various dysmorphic features. The next sibling, a boy, died of tetralogy of Fallot at the age of three months. He also had multiple vertebral and rib malformations. The subsequent girl, now eleven years old, has mental retardation, microcephaly and epilepsy along with facial dysmorphy, partial deafness and short stature. The eight-year-old child is slightly mentally retarded and microcephalic. A five-year-old boy was a premature, dystrophic baby and exhibits mental retardation, dysmorphic facial features, brachydactyly and clinodactyly of the fifth finger on both hands. Following a miscarriage, our index case, the youngest child at two years of age, is microcephalic and mentally retarded and shows minor facial anomalies. All children exhibit features of phenylalanine embryopathy caused by maternal phenylketonuria because the mother had not been diagnosed earlier and, therefore, never received any diet. CONCLUSION: This is the largest family suffering from maternal phenylketonuria reported in the literature. Maternal phenylketonuria remains a challenge, especially in woman from countries without a neonatal screening program. Therefore, it is mandatory to be alert for the possibility of maternal phenylketonuria syndrome in case of a child with the clinical features described here to prevent foetal damage in subsequent siblings.
Project description:Six submicroscopic deletions comprising chromosome band 2q23.1 in patients with severe mental retardation (MR), short stature, microcephaly and epilepsy have been reported, suggesting that haploinsufficiency of one or more genes in the 2q23.1 region might be responsible for the common phenotypic features in these patients. In this study, we report the molecular and clinical characterisation of nine new 2q23.1 deletion patients and a clinical update on two previously reported patients. All patients were mentally retarded with pronounced speech delay and additional abnormalities including short stature, seizures, microcephaly and coarse facies. The majority of cases presented with stereotypic repetitive behaviour, a disturbed sleep pattern and a broad-based gait. These features led to the initial clinical impression of Angelman, Rett or Smith-Magenis syndromes in several patients. The overlapping 2q23.1 deletion region in all 15 patients comprises only one gene, namely, MBD5. Interestingly, MBD5 is a member of the methyl CpG-binding domain protein family, which also comprises MECP2, mutated in Rett's syndrome. Another gene in the 2q23.1 region, EPC2, was deleted in 12 patients who had a broader phenotype than those with a deletion of MBD5 only. EPC2 is a member of the polycomb protein family, involved in heterochromatin formation and might be involved in causing MR. Patients with a 2q23.1 microdeletion present with a variable phenotype and the diagnosis should be considered in mentally retarded children with coarse facies, seizures, disturbed sleeping patterns and additional specific behavioural problems.
Project description:Rubinstein-Taybi syndrome or Broad Thumb-Hallux syndrome is a genetic disorder characterized by facial dysmorphism, growth retardation, and mental deficiency. A seven-year-old girl had come to the Department of Pedodontics, Istanbul Medipol University, Faculty of Dentistry, Turkey, with a complaint of caries and bleeding of gingivae. The patient was mentally retarded. Extraoral features revealed distinctive facial appearance with a broad fore head, hypertelorism, broad nasal bridge, and beaked nose. Intraoral features observed were talons cusps in the upper lateral incisors, carious teeth, and plaque accumulation. Since the patient was mentally retarded, the dental treatment was done under GA. The treatment plan and dental management of this patient are discussed in this case report.
Project description:INTRODUCTION: Microcephalic osteodysplastic primordial dwarfism is a syndrome characterized by the presence of intrauterine growth restriction, post-natal growth deficiency and microcephaly. Microcephalic osteodysplastic primordial dwarfism type II is the most distinctive syndrome in this group of entities. Individuals affected by this disease present at an adult height of less than 100 cm, a post-pubertal head circumference of 40 cm or less, mild mental retardation, an outgoing personality and bone dysplasia. CASE PRESENTATION: We report the first case of a five-year-old Colombian boy of mixed race ancestry (mestizo), with clinical features of microcephaly, prominent and narrow nose, arched palate, amelogenesis imperfecta, short stature, tall and narrow pelvis, disproportionate shortening of fore-arms and legs, and mild coxa vara. Analysis of the PCNT gene by sequencing showed the presence of a nucleotide change in exon 10, c. 1468C>T, evidencing a new mutation not reported in the literature for microcephalic osteodysplastic primordial dwarfism. CONCLUSION: The new mutation identified in this case could be associated with the severity of the phenotypic expression of the disease, resulting in the extreme short stature of the patient. Further studies are required to reach an explanation that can justify such findings, and it is vital to emphasize the importance of detection and follow-up by the epidemiological surveillance groups in birth defects and rare diseases.
Project description:Co-occurrence of primordial dwarfism and microcephaly together with particular skeletal findings are seen in a wide range of Mendelian syndromes including microcephaly micromelia syndrome (MMS, OMIM 251230), microcephaly, short stature, and limb abnormalities (MISSLA, OMIM 617604), and microcephalic primordial dwarfisms (MPDs). Genes associated with these syndromes encode proteins that have crucial roles in DNA replication or in other critical steps of the cell cycle that link DNA replication to cell division. We identified four unrelated families with five affected individuals having biallelic or de novo variants in DONSON presenting with a core phenotype of severe short stature (z score?<?-3 SD), additional skeletal abnormalities, and microcephaly. Two apparently unrelated families with identical homozygous c.631C?>?T p.(Arg211Cys) variant had clinical features typical of Meier-Gorlin syndrome (MGS), while two siblings with compound heterozygous c.346delG p.(Asp116Ile*62) and c.1349A?>?G p.(Lys450Arg) variants presented with Seckel-like phenotype. We also identified a de novo c.683G?>?T p.(Trp228Leu) variant in DONSON in a patient with prominent micrognathia, short stature and hypoplastic femur and tibia, clinically diagnosed with Femoral-Facial syndrome (FFS, OMIM 134780). Biallelic variants in DONSON have been recently described in individuals with microcephalic dwarfism. These studies also demonstrated that DONSON has an essential conserved role in the cell cycle. Here we describe novel biallelic and de novo variants that are associated with MGS, Seckel-like phenotype and FFS, the last of which has not been associated with any disease gene to date.
Project description:Microcephalic osteodysplastic primordial dwarfism syndrome II (MOPDII) is microcephalic primordial dwarfism and is a very rare form of disproportionate short stature. This disorder shares common features with other forms of microcephalic primordial dwarfism, including severe prenatal and postnatal growth retardation with marked microcephaly. However, it includes characteristic skeletal dysplasia, abnormal dentition and increased risk for cerebrovascular diseases. Recent reports added more features, including café-au-lait lesions, cutis marmorata, astigmatism, Moyamoya disease, insulin resistance, obesity, abnormal skin pigmentation and acanthosis nigricans around the neck. Clearly, the more MOPDII reports that are produced, the more information will be added to the spectrum of MOPDII features that can improve our understanding of this disorder. In this paper, we reported a new case of MOPDII with more severe clinical features, earlier onset of common features, in addition to a homozygous novel variant in the <i>PCNT</i> gene.
Project description:In a 2 and a half-year-old girl with onset of puberty before the age of 5 months, short stature, hand anomalies and severe mental retardation, an 8.9 Mb interstitial 19p13 duplication containing 215 predicted genes was detected. It was initially assumed that the duplication involved the kisspeptin receptor gene, GPR54, known to stimulate induction of puberty, but more refined duplication mapping excluded this possibility. In an attempt to further understand the genotype-phenotype correlation, global gene expression was measured in skin fibroblasts. The overall expression pattern was quite similar to controls, and only about 25% of the duplicated genes had an expression level that was increased by more than 1.3-fold, with no obvious changes that could explain the precocious puberty. The proband's mother carried a balanced between-arm insertion of the duplicated segment that resembled a pericentric inversion. The same insertion was found in several other family members, including one who had lost a daughter with severe mental retardation and menarche at the age of 10 years. Another close relative was severely mentally retarded, but neither dysmorphic nor microcephalic. His phenotype was initially ascribed to a presumed cryptic chromosome 19 imbalance caused by the 19p-into19q insertion, but subsequent array-CGH detected a 3.9-Mb deletion of 2q23.3q24.1. This novel microdeletion involves seven genes, of which FMNL2, a suggested regulator of Rho-GTPases, and NR4A2, an essential gene for differentiation of dopaminergic neurons, may be critical genes for the proposed 2q23q24 microdeletion syndrome.
Project description:This study reports a boy with psychomotor retardation and epilepsy due to maternal phenylketonuria (PKU). The boy was admitted at the age of 20 months because of psychomotor retardation and epilepsy. He had seizures from the age of 1 year. His development quotient was 43. He presented with microcephaly, normal skin and hair color. Brain MRI scan showed mild cerebral white matter demyelination, broadening bilateral lateral ventricle and foramen magnum stricture. Chromosome karyotype, urine organic acids, blood amino acids and acylcarnitines were normal. His mother had mental retardation from her childhood. She presented with learning difficulties and yellow hair. Her premarriage health examinations were normal. She married a healthy man at age of 26 years. When she visited us at 28 years old, PKU was found by markedly elevated blood phenylalanine (916.54??mol/L vs normal range 20-120??mol/L). On her phenylalanine hydroxylase (PAH) gene, a homozygous mutations c.611A>G (p.Y204C) was identified, which confirmed the diagnosis of PAH-deficient PKU. Her child carries a heterozygous mutation c.611A>G with normal blood phenylalanine. Her husband had no any mutation on PAH. It is concluded that family investigation is very important for the etiological diagnosis of the children with mental retardation and epilepsy. Carefully clinical and metabolic survey should be performed for the parents with mental problems to identify parental diseases-associated child brain damage, such as maternal PKU.
Project description:Microcephalic osteodysplastic primordial dwarfism type I (MOPD I) is a rare autosomal recessive developmental disorder characterized by extreme intrauterine growth retardation, severe microcephaly, central nervous system abnormalities, dysmorphic facial features, skin abnormalities, skeletal changes, limb deformations, and early death. Recently, mutations in the RNU4ATAC gene, which encodes U4atac, a small nuclear RNA that is a crucial component of the minor spliceosome, were found to cause MOPD I. MOPD I is the first disease known to be associated with a defect in small nuclear RNAs. We describe here the clinical and molecular data for 17 cases of MOPD I, including 15 previously unreported cases, all carrying biallelic mutations in the RNU4ATAC gene.
Project description:Searching for new genes involved in Mental Retardation. This research has also leaded to the identification of set of extraeneous up and down regulated genes of mentally retarded male and female subjects by comparing with normal reference.
Project description:<h4>Background</h4>Microcephalic osteodysplastic primordial dwarfism type II (MOPD II) is a rare autosomal recessive disorder characterized by severe pre- and postnatal growth restrictions, microcephaly, skeletal dysplasia, severe teeth deformities, and typical facial features. Previous studies have shown that MOPD II is associated with mutations in the pericentrin (PCNT) gene.<h4>Methods</h4>We evaluated the clinical features of a 10-year and 7-month-old Chinese girl with MOPD II. Subsequently, next-generation sequencing and flow cytometry were performed to investigate genetic characteristics and the expression of PCNT protein respectively.<h4>Results</h4>The patient presented with short stature, microcephaly, typical craniofacial features, teeth deformity, thrombocytosis, and a delayed bone age (approximately 7 years). No abnormality in growth hormone or insulin-like growth factor 1 was detected. Notably, the patient was found to carry a novel homozygous PCNT mutation (c.6157G>T, p.Glu2053Ter), which was inherited from her healthy heterozygous parents. Meanwhile, significant deficiency of PCNT expression was identified in the patient.<h4>Conclusion</h4>Our study identified a novel PCNT mutation associated with MOPD II, expanded the mutation spectrum of the PCNT gene and improved our understanding of the molecular basis of MOPD II.