Development, behaviour and sensory processing in Marshall-Smith syndrome and Malan syndrome: phenotype comparison in two related syndromes.

BACKGROUND: Ultrarare Marshall-Smith and Malan syndromes, caused by changes of the gene nuclear factor I X (NFIX), are characterised by intellectual disability (ID) and behavioural problems, although questions remain. Here, development and behaviour are studied and compared in a cross-sectional study, and results are presented with genetic findings. METHODS: Behavioural phenotypes are compared of eight individuals with Marshall-Smith syndrome (three male individuals) and seven with Malan syndrome (four male individuals). Long-term follow-up assessment of cognition and adaptive behaviour was possible in three individuals with Marshall-Smith syndrome. RESULTS: Marshall-Smith syndrome individuals have more severe ID, less adaptive behaviour, more impaired speech and less reciprocal interaction compared with individuals with Malan syndrome. Sensory processing difficulties occur in both syndromes. Follow-up measurement of cognition and adaptive behaviour in Marshall-Smith syndrome shows different individual learning curves over time. CONCLUSIONS: Results show significant between and within syndrome variability. Different NFIX variants underlie distinct clinical phenotypes leading to separate entities. Cognitive, adaptive and sensory impairments are common in both syndromes and increase the risk of challenging behaviour. This study highlights the value of considering behaviour within developmental and environmental context. To improve quality of life, adaptations to environment and treatment are suggested to create a better person-environment fit.

Chondrodysplasia with multiple dislocations: comprehensive study of a series of 30 cases.

The group of chondrodysplasia with multiple dislocations includes several entities, characterized by short stature, dislocation of large joints, hand and/or vertebral anomalies. Other features, such as epiphyseal or metaphyseal changes, cleft palate, intellectual disability are also often part of the phenotype. In addition, several conditions with overlapping features are related to this group and broaden the spectrum. The majority of these disorders have been linked to pathogenic variants in genes encoding proteins implicated in the synthesis or sulfation of proteoglycans (PG). In a series of 30 patients with multiple dislocations, we have performed exome sequencing and subsequent targeted analysis of 15 genes, implicated in chondrodysplasia with multiple dislocations, and related conditions. We have identified causative pathogenic variants in 60% of patients (18/30); when a clinical diagnosis was suspected, this was molecularly confirmed in 53% of cases. Forty percent of patients remain without molecular etiology. Pathogenic variants in genes implicated in PG synthesis are of major importance in chondrodysplasia with multiple dislocations and related conditions. The combination of hand features, growth failure severity, radiological aspects of long bones and of vertebrae allowed discrimination among the different conditions. We propose key diagnostic clues to the clinician.

A THANATOPHORIC DYSPLASIA TYPE I CASE WITH A FGFR3 P.R248C MUTATION AND SURVIVAL BEYOND THE NEONATAL PERIOD.

A Thanatophoric dysplasia, is a severe congenital anomaly which mostly causes stillbirth or death of the affected baby within hours due to respiratory insufficiency. The diagnosis of TD is typically suspected on ultrasound during the second trimester of pregnancy, when severe shortening of the long bones, frontal bossing, flattened vertebrae, and short ribs that result in a narrow thorax and bell-shaped abdomen, can be seen. Here, we present a case with prenatal ultrasonographic findings suggestive of TD, and highlight the patient's postnatal dysmorphic features and typical radiographic findings. The definitive diagnosis of TD type I (TDI) was made postnatally, when molecular genetic analysis revealed the previously described p.R248C mutation in FGFR3. This case is reported due to its relative long life span and the definitive molecular diagnosis that could be made during hospitalization.

Insights into genotype-phenotype correlations from CREBBP point mutation screening in a cohort of 46 Rubinstein-Taybi syndrome patients.

The genetic basis of Rubinstein-Taybi syndrome (RSTS), a rare, sporadic, clinically heterogeneous disorder characterized by cognitive impairment and a wide spectrum of multiple congenital anomalies, is primarily due to private mutations in CREBBP (approximately 55% of cases) or EP300 (approximately 8% of cases). Herein, we report the clinical and the genetic data taken from a cohort of 46 RSTS patients, all carriers of CREBBP point mutations. Molecular analysis revealed 45 different gene alterations including 31 inactivating (21 frameshift and 10 nonsense), 10 missense and 4 splicing mutations. Bioinformatic tools and transcript analyses were used to predict the functional effects of missense and splicing alterations. Of the 45 mutations, 42 are unreported and 3 were described previously. Recurrent mutations maybe a key tool in addressing genotype-phenotype correlations in patients sharing the same defects (at the genomic or transcript level) and specific clinical signs, demonstrated here in two cases. The clinical data of our cohort evidenced frequent signs such as arched eyebrows, epicanthus, synophrys and/or frontal hypertrichosis and broad phalanges that, previously overlooked in RSTS diagnosis, now could be considered. Some suggested correlations between organ-specific anomalies and affected CREB-binding protein domains broaden the RSTS clinical spectrum and perhaps will enhance patient follow-up and clinical care.

Mutations and polymorphisms in N-acetylgalactosamine-6-sulfate sulfatase gene in Turkish Morquio A patients.

Mucopolysaccharidosis type IVA (MPS IVA) is an autosomal recessive inherited metabolic disease resulting from deficiency of N-acetylgalactosamine-6-sulfatase (GALNS). This lysosomal storage disorder leads to a wide range of clinical variability ranging from severe, through intermediate to mild forms. The classical phenotype of Morquio A disease is characterized by severe bone dysplasia without intellectual impairment. Two severe MPS IVA patients from two unrelated Turkish families have been investigated. The 14 exons and intron-exon junctions of the GALNS gene were sequenced after amplification from genomic DNA. Direct sequencing revealed two homozygous mutations previously described: p.L390X in exon 11 and p.W141R in exon 4. The p L390X mutation was associated with four novel polymorphisms in intron 2, intron 5 and intron 6 and one polymorphism previously described in exon 7. We have analysed the haplotypes associated with the two identified mutations. These molecular findings will permit accurate carrier detection, prenatal diagnosis and counseling for Morquio A syndrome in Turkey.

Werner syndrome: clinical evaluation of two cases and a novel mutation.

Werner syndrome (WS) is a premature aging disorder, inherited in an autosomal recessive pattern and caused by the mutation in the WRN gene. In this report we describe two male patients with negative family history who demonstrate characteristic findings of WS, with different mutations, including one novel mutation. The first case was a 47-year-old man who had been suffering from large, ischemic ulcers on both legs for 7 years. Physical examination revealed a thin and short man with severe wasting of all extremities. He had a high-pitched voice, hoarseness, a characteristic bird-like facies, bilateral cataracts, generalized osteoporosis, hypotrichosis, atrophic and poikilodermic skin, flexion contractures of hands, feet and knees, and soft tissue calcifications. Laboratory investigations revealed anemia, high erythrocyte sedimentation rate, low creatinine clearance, and high liver enzymes. Genetic analysis showed a homozygous novel 1bp-deletion in exon 19 of WRN, 2426/27delG, causing frameshift and protein truncation R809SfsX2, which has not been described before. The second case was a 23-year-old man who was referred for large callosities on both feet, present for 7 years. He complained of weakness, weight loss, wasting of muscles, and early graying of hair. The entire skin was thin, wrinkled and dry. Generalized hypotrichosis, scattered ephelid-like macules, sclerotic fingers, calcinosis cutis on ears, hyperpigmentation on elbows were the other alterations of skin. Skeletal survey revealed osteoporosis. Genetic analysis showed a homozygous known pathogenic splice site mutation c.3460-2A>G, causing skipping of Exon 30 in WRN.

Confirming genes influencing risk to cleft lip with/without cleft palate in a case-parent trio study.

A collection of 1,108 case-parent trios ascertained through an isolated, nonsyndromic cleft lip with or without cleft palate (CL/P) was used to replicate the findings from a genome-wide association study (GWAS) conducted by Beaty et al. (Nat Genet 42:525-529, 2010), where four different genes/regions were identified as influencing risk to CL/P. Tagging SNPs for 33 different genes were genotyped (1,269 SNPs). All four of the genes originally identified as showing genome-wide significance (IRF6, ABCA4 and MAF, plus the 8q24 region) were confirmed in this independent sample of trios (who were primarily of European and Southeast Asian ancestry). In addition, eight genes classified as 'second tier' hits in the original study (PAX7, THADA, COL8A1/FILIP1L, DCAF4L2, GADD45G, NTN1, RBFOX3 and FOXE1) showed evidence of linkage and association in this replication sample. Meta-analysis between the original GWAS trios and these replication trios showed PAX7, COL8A1/FILIP1L and NTN1 achieved genome-wide significance. Tests for gene-environment interaction between these 33 genes and maternal smoking found evidence for interaction with two additional genes: GRID2 and ELAVL2 among European mothers (who had a higher rate of smoking than Asian mothers). Formal tests for gene-gene interaction (epistasis) failed to show evidence of statistical interaction in any simple fashion. This study confirms that many different genes influence risk to CL/P.

A short rib polydactyly syndrome overlapping both lethal and nonlethal types.

Short rib polydactyly syndrome (SRPS) type II is a rare, autosomal recessively inherited, lethal skeletal dysplasia characterized by polydactyly, short limbs, short and horizontal ribs, a short ovoid tibia and major organ anomalies. We report a patient with a fetus with SRPS type II that presented at the 19th week of pregnancy for amniocentesis because of maternal age. During ultrasound pre-axial synpolydacytly, a short and ovoid tibia, nuchal edema, vertebral irregularities, hypoplastic thorax with short ribs and talipes were detected. All of the extremities were under the 5th percentile. Thorax-abdomen ratio was 0,56. The family was counselled for a diagnosis of lethal SRPS. After termination of pregnancy, radiological and histopathological examination allowed us to reach the diagnosis ofMajewski syndrome (SRPS type II). SRPSs are a continuous spectrum of both lethal and nonlethal forms. Prenatal diagnosis and termination depending on ultrasound findings should be done very precociously considering different phenotypic expressions, even in families previously affected by a lethal SRPS.

A novel loss-of-function mutation in the GNS gene causes Sanfilippo syndrome type D.

UNLABELLED: A novel loss-of-function mutation in the GNS gene causes Sanfilippo syndrome type D: Mucopolysaccharidosis type IIID (MIM 252940) is the least common form of the four subtypes of Sanfilippo syndrome. It is an autosomal recessive lysosomal disorder caused by a deficiency of the N-acetylglucosamine-6-sulphatase (GlcNAc-6S sulphatase, GNS), a hydrolase, which is one of the enzymes involved in heparan sulfate catabolism leading to lysosomal storage. The clinical features of this disorder are progressive neurodegeneration with relatively mild somatic symptoms. Twenty patients have been described in the literature and only seven causative mutations in the GNS gene encoding GlcNAc-6S sulphatase have been reported to date. We present the clinical and molecular results of a newly diagnosed Turkish patient with MPS IIID. We identified the novel homozygous single base pair insertion, c.1226GinsG, which leads to a frame-shift and a premature truncation of the GNS protein (p.R409Rfs21X). CONCLUSION: This novel mutation provides further evidence that loss-of-function is the underlying pathophysiological mechanism of this rare phenotype.

Molecular characterisation of six patients with prolidase deficiency: identification of the first small duplication in the prolidase gene and of a mutation generating symptomatic and asymptomatic outcomes within the same family.

Prolidase deficiency (PD) is a rare autosomal recessive connective tissue disorder caused by mutations in the prolidase gene. The PD patients show a wide range of clinical outcomes characterised mainly by intractable skin ulcers, mental retardation and recurrent respiratory infections. Here we describe five different PEPD mutations in six European patients. We identified two new PEPD mutant alleles: a 13 bp duplication in exon 8, which is the first reported duplication in the prolidase gene and a point mutation resulting in a change in amino acid E412, a highly conserved residue among different species. The E412K substitution is responsible for the first reported phenotypic variability within a family with severe and asymptomatic outcomes.

Prenatal diagnosis of Wolf-Hirschhorn syndrome (4p-) in association with congenital diaphragmatic hernia, cystic hygroma and IUGR.

Wolf-Hirschhorn syndrome (WHS) is a rare distinct clinical entity caused by a deletion of the short arm of chromosome 4. We report a case in which intrauterine growth restriction (IUGR), severe oligohydramnios, left-sided congenital diaphragmtic hernia (CDH), and cystic hygroma were detected by prenatal ultrasound examination at 27 weeks of gestation. A 29-year-old gravida 3, para 2, woman was referred at 26 weeks' gestation with suspicion of IUGR and cystic hygroma. Sonographic examination revealed IUGR with severe oligohydramnios, increased nuchal fold with cystic hygroma (left-sided diaphragmatic defect of Bochdalek type), and congenital diaphragmatic hernia. Chromosome analysis revealed a 46, XX, del(4)(p15.2) karyotype. Autopsy confirmed the ultrasound findings. Congenital diaphragmatic hernia (CDH) has rarely been described to be associated with WHS. CDH and cystic hygroma can lead to a diagnosis of this syndrome very early in life. We recommend genetic evaluation of a fetus with cystic hygroma, IUGR and CDH taking into consideration 4p deletion syndrome.

Dermatoglyphics in patients with Cenani-Lenz type syndactyly: studies in a new case.

We describe an additional case of Cenani-Lenz syndactylism in a 4 1/2-year-old boy from a consanguineous Turkish family. The digital anomalies consisted partly of synostosis and partly of malformations of the phalanges. Although there was no radio-ulnar synostosis or abnormality of the bones of the feet, the findings are comparable to those described in the Cenani-Lenz type of syndactyly. We analysed the dermatoglyphics of our patient and compared them with those previously reported. We also investigated the relationship between the bony malformations and the dermatoglyphic patterns in our patient and in the literature.

Temporal aspects in craniometaphyseal dysplasia: autosomal recessive type.

We present the clinical and radiographic findings in a patient with the autosomal recessive form of craniometaphyseal dysplasia (CMD). The changes from infancy to the age of 17 years are illustrated and discussed.

Spondylometaphyseal dysplasia-Sedaghatian type.

We present the radiological findings in two unrelated cases with spondylometaphyseal dysplasia type Sedaghatian. We review the literature and identify additional anomalies including disproportionately long fibulae, dysharmonious maturation and turricephaly.

Peroxisomal disorders: clinical and biochemical studies in 15 children and prenatal diagnosis in 7 families.

We describe the main clinical and biochemical findings in 15 patients with peroxisomal disorders, together with the results of 11 prenatal investigations for Zellweger syndrome. The initial laboratory diagnosis depended in most cases on demonstration of elevated very long chain fatty acids in plasma, but follow-up studies using cultured fibroblasts were essential for complete classification. The patient group comprises nine cases of Zellweger syndrome, one of neonatal adrenoleucodystrophy, two of infantile Refsum disease, one of bifunctional protein deficiency, and two of rhizomelic chondrodysplasia punctata. The study illustrates the clinical and biochemical variability of this group of patients and the detailed studies that are required for classification.

Persistent müllerian duct syndrome. A case report.

BACKGROUND: Persistent müllerian duct syndrome is a rare form of male pseudohermaphroditism in which well-developed müllerian structures are present in an otherwise normal male with XY chromosomes. The syndrome was first described by Nilson in 1939, and almost 100 cases have been reported. CASE: A 22-year-old man presented with mild, right-sided inguinal pain and heaviness in his scrotum. He underwent right-sided inguinal exploration because of having a palpable right-sided, irreducible inguinal hernia. Two testicles with surface nodularity and a bicornuate uterus with rudimentary fallopian tubes were detected and removed as one specimen, and the hernia was repaired. CONCLUSION: Management of this syndrome is difficult because of the limited number of cases. If the diagnosis can be made before surgery, karyotyping can be useful to decide on orchiopexy or orchioectomy. In suspected cases, laparoscopy and ultrasonographic evaluation of all crytorchidic cases may be helpful for diagnosing this condition before surgery. All patients with this syndrome have a male phenotype; therefore, it is essential to preserve secondary sex characteristics. Androgen replacement therapy should be given to patients who have undergone gonadectomy and to those with low levels of testosterone.

The frequency of genetic eye diseases in a genetic counseling center.

The frequency of genetic eye diseases in a genetic counseling center: In this study the incidence of eye diseases of genetic origin in patients attending our genetic counseling center for a period of almost six years is documented. The frequency of retinitis pigmentosa, congenital cataracts, lens dislocation, microphthalmos, retinoblastoma, congenital glaucoma, congenital ptosis, degenerative myopia, strabismus, optic atrophy, various genetic metabolic diseases have been investigated, and the results are presented. Preventive approaches and prenatal diagnostic possibilities are discussed and the importance of genetic counseling is emphasized.

Monozygotic twins discordant for the oculo-oto-radial syndrome (IVIC syndrome).

Monozygotic twins are rarely completely identical despite their origin from a single zygote. The twinning process itself, or the very early intrauterine environment must provide the clues to explain this developmental dilemma. We present here discordant monozygotic twin girls, one of whom was diagnosed having IVIC (Oculo-oto-radial) syndrome on the basis of hand abnormalities and hearing loss but her twin sister has only strabismus. The family has at least 7 apparently and 2 possible affected members (gene carriers) over four generations, the majority being only midly affected. The 2 girls, whose monozygosity has been proved using independent DNA loci, show marked variability in expression, showing that for this gene modification of expression must be epigenetic or environmental rather than genetic.

A variant of Cenani-Lenz type syndactyly.

Cenani-Lenz syndrome is a form of complete syndactyly resembling the spoon hand in Apert syndrome. It is often associated with disorganization of phalanges, the fusion of metacarpals and mesomelic shortness of the arm. We describe an additional case of Cenani-Lenz type of syndactylism in a 16 month-old girl who also has rib and vertebral abnormalities and mixed type hearing loss, that have not been seen before in a single patient.

Tuberous sclerosis: clinical evaluation in a family and implications for genetic counseling.

Tuberous sclerosis is an autosomal-dominant neurocutaneous disease, characterized by hamartomas in various organs. In a nuclear family, three persons in two generations were diagnosed as having tuberous sclerosis, with multiple hypomelanotic dermal patches and epilepsy. Computerized tomography showed subependymal calcifications and ophthalmological investigations indicated phakomas as retinal involvement in all of them. Two distinct chromosomal loci are linked to tuberous sclerosis complex, and carrier detection and prenatal diagnosis approaches are being developed. Genetic counseling is very important in this devastating disease with high penetrance, particularly because of its broad spectrum and variability of manifestations.