Perinatal and early infantile symptoms in congenital disorders of glycosylation

Congenital disorders of glycosylation (CDG) are a rapidly growing family of inborn errors. Screening for CDG in suspected cases is usually performed in the first year of life by serum transferrin isoelectric focusing or mass spectrometry. Based on the transferrin analysis patients can be biochemically diagnosed with a type 1 or type 2 transferrin pattern, and labeled as CDG‐I, or CDG‐II. The diagnosis of CDG is frequently delayed due to the highly variable phenotype, some cases showing single organ involvement and others mimicking syndromes, like skeletal dysplasia, cutis laxa syndrome, or congenital muscle dystrophy. The aim of our study was to evaluate perinatal abnormalities and early discriminative symptoms in 58 patients consecutively diagnosed with diverse CDG‐subtypes. Neonatal findings and clinical features in the first months of life were studied in 36 children with CDG‐I and 22 with CDG‐II. Maternal complications were found in five, small for gestational age in nine patients. Five children had abnormal neonatal screening results for hypothyroidism. Congenital microcephaly and neonatal seizures were common in CDG‐II. Inverted nipples were uncommon with 5 out of 58 children. Dysmorphic features were mostly nonspecific, except for cutis laxa. Early complications included feeding problems, cardiomyopathy, thrombosis, and bleeding. Cases presenting in the neonatal period had the highest mortality rate. Survival in CDG patients is highly dependent on early intervention therapy. We recommend low threshold screening for glycosylation disorders in infants with neurologic symptoms, even in the absence of abnormal fat distribution. Growth retardation and neonatal bleeding increase suspicion for CDG. © 2013 Wiley Periodicals, Inc.     

Abnormal folate metabolism and genetic polymorphism of the folate pathway in a child with Down syndrome and neural tube defect

The association of neural tube defects (NTDs) with Down syndrome (trisomy 21) and altered folate metabolism in both mother and affected offspring provide a unique opportunity for insight into the etiologic role of folate deficiency in these congenital anomalies. We describe here the case of a male child with trisomy 21, cervical meningomyelocele, agenesis of corpus callosum, hydrocephaly, cerebellar herniation into the foramen magnum, and shallow posterior cranial fossa. Molecular analysis of the methylenetetrahydrofolate (MTHFR) gene revealed homozygosity for the mutant 677C-->T polymorphism in both the mother and child. The plasma homocysteine of the mother was highly elevated at 25.0 micromol/L and was associated with a low methionine level of 22.1 micromol/L. Her S-adenosylhomocysteine (SAH) level was three times that of reference normal women, resulting in a markedly reduced ratio of S-adenosylmethionine (SAM) to SAH and significant DNA hypomethylation in lymphocytes. The child had low plasma levels of both homocysteine and methionine and a reduced SAM/SAH ratio that was also associated with lymphocyte DNA hypomethylation. In addition, the child had a five-fold increase in cystathionine level relative to normal children, consistent with over-expression of the cystathionine beta synthase gene present on chromosome 21. We suggest that altered folate status plus homozygous mutation in the MTHFR gene in the mother could promote chromosomal instability and meiotic non-disjunction resulting in trisomy 21. Altered folate status and homozygous TT mutation in the MTHFR gene in both mother and child would be expected to increase the risk of neural tube defects. The presence of both trisomy 21 and postclosure NTD in the same child supports the need for an extended periconceptional period of maternal folate supplementation to achieve greater preventive effects for both NTD and trisomy 21.     

Hypotonia, developmental delay and features of scalp-ear-nipple syndrome in an inbred Arab family

We report two children from an inbred Arab family with features suggestive of scalp-ear-nipple syndrome who in addition had severe hypotonia and developmental delay. Also addition, other features seen in scalp-ear-nipple syndrome such as camptodactyly, syndactyly and dry skin were absent in these children. We suggest the children in this report have a severe recessive form of this syndrome.     

Identification of a locus for a form of spondyloepiphyseal dysplasia on chromosome 15q26.1: exclusion of aggrecan as a candidate gene

We have investigated a family with an autosomal dominant form of spondyloepiphyseal dysplasia (SED) characterised by short stature and severe premature degenerative arthropathy. Previous studies have excluded linkage between this condition and the locus for the type II collagen gene. Here we report the identification of linkage between this disorder and a locus on the long arm of chromosome 15 between markers D15S979 and D15S1004. According to current linkage maps and sequence data, this locus includes that of the aggrecan gene (AGC1). Our linkage data from the SED family show, however, that AGC1 maps to a locus that is proximal to D15S979. This proximal location for AGC1 is further supported by linkage data from a second family with an autosomal recessive form of multiple epiphyseal dysplasia that also maps to the SED locus. In both families AGC1 is therefore excluded as a candidate gene.     

Absent pituitary gland and hypoplasia of the cerebellar vermis associated with partial ophthalmoplegia and postaxial polydactyly: a variant of orofaciodigital syndrome VI or a new syndrome?

We report two sibs with features overlapping those of orofaciodigital syndrome type VI (Varadi syndrome). Both presented at birth with oculomotor abnormalities, dysmorphic facial features, and dysgenesis of the cerebellar vermis. There were minimal oral manifestations (high arched palate) in both of them and one had postaxial polydactyly of both hands and one foot. In addition, there was evidence of aplasia of the pituitary gland on MRI scan in both of them with evidence of hypopituitarism. Both responded well to hormone replacement therapy with improvement in their linear growth and mental ability. These cases may represent a new autosomal recessive midline defect syndrome with features overlapping OFDS VI. Alternatively the features in these children could represent variability within OFDS VI.     

Organisation of the human PAX4 gene and its exclusion as a candidate for the Wolcott-Rallison syndrome.

Neonatal diabetes mellitus is a rare condition, the causes of which are mostly unknown. One well defined though very rare entity is the autosomal recessive Wolcott-Rallison syndrome, in which permanent neonatal diabetes, osteopenia, and epiphyseal dysplasia occur. Only five previous families have been reported, and here we describe the second in which parental consanguinity was present. The proband was born to first cousin parents and died at 2 years from the sequelae of poorly controlled diabetes. To test the hypothesis that mutation of PAX4, required in the mouse for pancreatic islet beta cell development, might cause WRS, the structure of the human PAX4 gene was deduced and DNA from two unrelated WRS patients sequenced. No PAX4 mutation was present, though the entire coding region was sequenced in both patients. It therefore appears unlikely that PAX4 is involved in the aetiology of Wolcott-Rallison syndrome, though it remains a good candidate for other forms of neonatal diabetes mellitus.     

Electroencephalography, Doppler vascular scanning, and single photon emission computed tomography in a child with hydranencephaly and intractable seizures

In a child with hydranencephaly and refractory seizures, the electroencephalogram showed a flat isoelectric pattern with no significant slow waves or epileptiform activity; cranial computed tomography, magnetic resonance imaging, Doppler vascular scanning, and single photon emission computed tomography (SPECT) were done to define the pathogenesis of the seizures. The investigations were suggestive of a lack of significant cortical, subcortical, or thalamic structures with hypoplasia of the vermis and cerebellum. SPECT showed little activity in the base of the brain and cerebellum. The cause of the seizures remained unclear in spite of the investigations.     

Stüve-Wiedemann syndrome in children surviving infancy: clinical and radiological features

We report three children from two inbred Arab families with Stüve-Wiedemann syndrome who have survived the first year of life (ages are 6 years, 2.8 years and 2 years). All exhibited a characteristic phenotype resembling that described by Chen et al.[(2001). Am J Med Genet 101:240-245]. In all three children the skeletal abnormalities progressed to severe bowing of the long bones with prominent joints and severe spinal deformity. Neurological symptoms were present in all of them. These included temperature instability with excessive sweating, reduced pain sensation with repeated injury to the tongue and limbs, absent corneal reflexes and a smooth tongue. Mentality was normal in all of them. Radiological changes included under tubulation of the diaphyses, rarefaction and striation of metaphyses, destruction of the femoral heads and spinal deformity. We confirm that survival in this syndrome is possible and that the prognosis improves after the first year of life. This should be taken into consideration when counselling parents of affected children. This report further supports the existence of a characteristic phenotype in Stüve-Wiedemann syndrome survivors which include, in addition to the skeletal abnormalities and distinctive radiological features, neurological symptoms reminiscent of dysautonomia.