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This review covers congenital hair shaft anomalies, which are conditions affecting hair shaft morphology. Sometimes suspected with the naked eye, often in need of microscopic examination to properly diagnose, these conditions could lead to the discovery of a complex genetic syndrome. Further knowledge is needed in order to establish a diagnosis, approach treatment alternatives and shed light on prognoses, which benefits patients. Our aim is to provide an updated summary of pathogenesis, clinical findings, treatment options and prognosis as well as psychosocial impact.

Noonan syndrome is part of the group of RASopathies caused by germ line mutations in genes involved in the RAS/MAPK pathway. There is substantial phenotypic overlap among the RASopathies. Diagnosis of Noonan syndrome is often based on clinical features including dysmorphic facial features, short stature and congenital heart disease. Rapid advances in sequencing technology have made molecular genetic analyses a helpful tool in diagnosing and distinguishing Noonan syndrome from other RASopathies.

A new classification of inherited ichthyoses is presented based on clinical features, genetic background and pathophysiology. Ichthyoses are disorders of cornification and may be part of syndromes. Ichthyosis vulgaris, X-linked ichthyosis, autosomal recessive congenital ichthyosis and syndrome-related variants are described. Severe forms can be potentially life-threatening. Dry scaly skin can be disabling and time-consuming, as the patient needs topical therapy and sometimes also systemic retinoids. Treatment today is symptomatic, but hopefully new knowledge will lead to targeted therapies.

Porphyrias are rare, distinct and well characterized diseases due to impairment of one of the eight steps in the biosynthesis of haem, which is the functional group of haemoglobin, myoglobin and cytochromes, including the cytochrome P-450 family. The actual strategies for diagnosis and biochemical control of the five most common porphyrias are described.

Introduction: In 2004 the Danish National Board of Health issued new guidelines for prenatal diagnostics in Denmark. The guidelines include a general offer to all pregnant women in Denmark of first trimester risk assessment of combined non-invasive tests integrating measurement of nuchal translucency and maternal biochemistry for detection of fetal chromosomal abnormalities like trisomy 21, and replacing the screening criteria of > or =35 of age., Materials and Methods: The study is based on registered data covering 5,504 pregnancies during the period 1 July 2005 to 31 December 2005 in Aarhus and Viborg Counties., Results: 77% of the pregnant women had a complete combined test and only 2% declined the program. At a cut off at 1:400 at term the detection rate for trisomy 21 was 85% (CI: 62.1-96.8%) with a false positive rate of 3.4%. There was a significant reduction in the number of prenatal karyotypes from 2002 to 2005 in both counties, with a 58% reduction in Viborg County and 33% in Aarhus County. The percentage of abnormal karyotypes over the same period increased from 2.8%% to 11.4% in Viborg County, and from 7.1% to 15.4% in Aarhus County., Conclusion: With a significant reduction in invasive procedures and a detection rate of 85% with a false positive rate of 3.4%, the results of the first trimester risk assessment program comply with the requirements defined by the Danish National Board of Health.

Eight patients with pycnodysostosis from six Danish families were examined for mutations in the cathepsin K gene. Three different mutations are the cause of pycnodysostosis in the six families--five of whom come from Ringkøbing County and one from Vejle County. One mutation has a high frequency in the families from Ringkoebing County. The five families are related through a common ancestor, who introduced the mutation around the year 1100. The disease is described with respect to aetiology, symptoms, prognosis, diagnosis, and symptomatic treatment. Research in pycnodysostosis may bring important knowledge to the understanding of related diseases, such as osteoporosis.

A female infant born at term, with reduced fetal movements in utero, congenital multiple contractures, severe weakness at birth, and a short time of survival is described. The diagnosis was confirmed by identification of homozygous deletion of exons 7 and 8 of the SMNt gene. Severe spinal muscular atrophy should be considered in the differential diagnosis of reduced fetal movements.

Fibroblast growth factors are structurally related proteins associated with cell growth, differentiation, migration, wound healing, angiogenesis, and oncogenesis. At the cellular level, their function is mediated by transmembrane tyrosinekinase receptors, fibroblast growth factor receptors. Four genes encoding fibroblast growth factor receptors have been identified, and mutations in three of these, FGFR1, FGFR2, and FGFR3, can cause different congenital, autosomal dominant disorders affecting the craniofacial and skeletal development: craniosynostosis and chondrodysplasias. The craniosynostosis syndromes: Apert syndrome, Beare-Stevenson syndrome, Crouzon syndrome, Jackson-Weiss syndrome, Muenke syndrome, Pfeiffer syndrome and Saethre-Chotzen syndrome can be caused by mutation in either FGFR1, FGFR2, or FGFR3. Saethre-Chotzen syndrome can also be caused by mutation in a functionally related gene, ACS. The same mutation can cause different syndromes, and the same syndrome can be caused by mutations in different genes. The chondrodysplasias: achondroplasia, hypochondroplasia, and thanatophoric dysplasia are all caused by mutations in FGFR3.

Hereditary neuropathy with liability to pressure palsies (HNPP) is an autosomal dominant disorder characterized by recurrent transient pressure palsies of peripheral nerves and slowing of nerve conduction velocity of the peripheral nerves at common sites of compression. In most cases the molecular basis of the disease is a 1.5 Mb deletion on chromosome 17p11.2. We report four members of a family with different clinical phenotypes. Electrophysiological and genetic studies were consistent with the diagnosis of HNPP. Nerve biopsy is only necessary in patients with a normal result of the molecular genetic analysis. The variability of the clinical phenotype along with asymptomatic individuals could account for an under-recognition of this inherited neuropathy.

Neuronal ceroid-lipofuscinosis is a group of neurodegenerative diseases which are characterized by an abnormal accumulation of lipopigment in neuronal and extraneuronal cells. The diseases can be differentiated into several subgroups according to age of onset, the clinical picture, neurophysiological and neuropathological abnormalities and ultrastructural studies documenting different profiles of the lipopigment. Several eponyms have been used in the designation of the diseases. Latest, an international designation abbreviated CLN has been recommended, with the addition of figures according to the subtypes. The most common type in Denmark is CLN3, also called Spielmeyer-Vogt's disease. The incidence is 1.6 per 100,000. It is characterized by slowly progressing behavioral and visual symptoms that start when the child is about four to nine years old. During the second decade of life, the disease is accompanied by seizures and severe psychomotor deterioration. Most patients die before the age of 30 years. Recently, it has been shown that this type of CLN disease is due to a mutation in a gene located on chromosome 16 (16p 12.1). A brief description of the other subtypes of CLN is given.

If oligohydramnios, growth retardation or foetal malformations are demonstrated by ultrasonic scanning in the second or third trimesters, this implies that the risk of chromosome anomalies is significantly increased. In cases such as these, determination of the foetal karyotype may therefore be indicated. Until recently, amniocentesis has been employed for this but the results of the chromosome investigation are not available until two to three weeks after the intervention. The delay between amniocentesis and the result of chromosome investigation imposes a mental strain on the pregnant woman. Three patients with abnormal ultrasonic findings in the second trimester were, therefore, submitted to transabdominal chorion villus biopsy and, in all three cases, a karyotype was available within 48 hours. Chorion villus biopsy in the second (and third) trimester is indicated in pregnancies in which oligohydramnios, growth retardation or foetal malformations have been demonstrated by ultrasonic scanning, in cases where referral for antenatal diagnosis is very late and when chromosome investigation after amniocentesis proves unsuccessful and repeated amniocentesis would result in an unacceptably late result.