GABRA1 mutations make a significant contribution to the genetic etiology of both benign and severe epilepsy syndromes. Myoclonic and tonic-clonic seizures with pathologic response to photic stimulation are common and shared features in both mild and severe phenotypes.

Vitamin B12 deficiency seems to be more common worldwide than previously thought. However, only a few reports based on data from newborn screening (NBS) programs have drawn attention to that subject. In Estonia, over the past three years, we have diagnosed 14 newborns with congenital acquired vitamin B12 deficiency. Therefore, the incidence of that condition is 33.8/100,000 live births, which is considerably more than previously believed. None of the newborns had any clinical symptoms associated with vitamin B12 deficiency before the treatment, and all biochemical markers normalized after treatment, which strongly supports the presence of treatable congenital deficiency of vitamin B12. During the screening period, we began using actively ratios of some metabolites like propionylcarnitine (C3) to acetylcarnitine (C2) and C3 to palmitoylcarnitine (C16) to improve the identification of newborns with acquired vitamin B12 deficiency.In the light of the results obtained, we will continue to screen the congenital acquired vitamin B12 deficiency among our NBS program. Every child with aberrant C3, C3/C2 and C3/C16 will be thoroughly examined to exclude acquired vitamin B12 deficiency, which can easily be corrected in most cases.

along with other distinctive characteristics like asymmetry of body and limbs, craniofacial features, and 5th finger (F5) clinodactyly. Beckwith-Wiedemann syndrome (BWS, OMIM: 130650) is also a growth-affecting disorder which causes overgrowth with many additional clinical features like macroglossia, organomegaly, and increased risk of childhood tumors [Weksberg et al., 2010]. The most common molecular cause for both syndromes is an abnormal regulation of genes in chromosomal region 11p15 [Gicquel et al., 2005], where 2 imprinting control regions (ICR1 and ICR2) control fetal and postnatal growth. ICR1 contains the maternally expressed H19 gene and the paternally expressed IGF2 gene, whereas ICR2 contains the maternally expressed KCNQ1 and CDKN1C genes and the paternally expressed KCNQ1OT1 gene. Normally, genes that are expressed in 1 allele are imprinted (methylated) and silenced in the other allele. Imprinting disturbances lead to abnormal expression of these genes and the clinical phenotypes of SRS or BWS. Approximately 40% of SRS patients show hypomethylation of ICR1, whereas up to 50% of BWS patients have ICR2 hypomethylation [Eggermann et al., 2008]. In addition, in SRS and BWS patients, numerous submicroscopic chromosomal disturbances have been described, among them duplications, deletions, inversions and/or translocations affecting chromosome 11p15 [Begemann et al., 2012;Fokstuen and Kotzot, 2014]. Large duplicaKey Words 11p15 duplication · 11p15 imprinting disorders · Beckwith-Wiedemann syndrome · Imprinting control region 1 · Imprinting control region 2 · Silver-Russell syndrome Abstract Silver-Russell syndrome (SRS) and Beckwith-Wiedemann syndrome (BWS) are 2 opposite growth-affecting disorders. The common molecular cause for both syndromes is an abnormal regulation of genes in chromosomal region 11p15, where 2 imprinting control regions (ICR) control fetal and postnatal growth. Also, many submicroscopic chromosomal disturbances like duplications in 11p15 have been described among SRS and BWS patients. Duplications involving both ICRs cause SRS or BWS, depending on which parent the aberration is inherited from. We describe to our knowledge the smallest familial pure 1.3-Mb duplication in chromosomal region 11p15.5p15.4 that involves both ICRs and is present in 3 generations causing an SRS or BWS phenotype.

LEOPARD syndrome (LS) is a heterogeneous disease characterised mainly by cutaneous manifestations. LEOPARD is the acronym for its major features-multiple lentigines, electrocardiographic conduction defects, ocular hypertelorism, pulmonary stenosis, abnormalities of (male) genitalia, retardation of growth and sensorineural deafness. As clinical manifestations are variable, molecular testing is supportive in the diagnosis of LS. We describe two unrelated LS cases with a common PTPN11 mutation Y279C and with completely different clinical features including distinct changes in skin pigmentation. In patient 1, the first complaint was hyperactive behaviour. First lentigines were presented at birth, but intensive growth began at the age of 2-4 years. Multiple dark lentigines were located mainly on the face and the upper part of the trunk, but the oral mucosa was spared. Patient 2 was born from induced labour due to polyhydramnion, and in the second week of life, mitral valve insufficiency and hypertrophic cardiomyopathy were diagnosed. Rapid growth of lentigines began at the age of 3 years. These are mostly located in the joint areas in the lower extremities; the face and upper trunk are spared from lentigines. In both cases, the rapid growth of lentigines made it possible to shift the diagnosis towards LS. Clinicians should give more consideration to rare genetic syndromes, especially in the case of symptoms from different clinical areas.

Background Multiple acyl‐CoA dehydrogenase deficiency (MADD), also known as glutaric aciduria type II, is a mitochondrial fatty acid oxidation disorder caused by variants in ETFA, ETFB, and ETFDH. Recently, riboflavin transporter genes and the mitochondrial FAD transporter gene have also been associated with MADD‐like phenotype. Methods We present a case of MADD identified by newborn biochemical screening in a full‐term infant suggestive of both medium‐chain acyl‐CoA dehydrogenase deficiency and MADD. Urine organic acid GC/MS analysis was also concerning for both disorders. However, panel sequencing of ETFA, ETFB, ETFDH, and ACADM was unrevealing. Ultimately, a variant in the FAD synthase gene, FLAD1 was found explaining the clinical presentation. Results Exome sequencing identified compound heterozygous variants in FLAD1: NM_025207.4: c.[442C>T];[1588C>T], p.[Arg148*];[Arg530Cys]. The protein damaging effects were confirmed by Western blot. The patient remained asymptomatic and there was no clinical decompensation during the first year of life. Plasma acylcarnitine and urinary organic acid analyses normalized without any treatment. Riboflavin supplementation was started at 15 months. Conclusion Newborn screening, designed to screen for specific treatable congenital metabolic diseases, may also lead to the diagnosis of additional, very rare metabolic disorders such as FLAD1 deficiency. The case further illustrates that even milder forms of FLAD1 deficiency are detectable in the asymptomatic state by newborn screening.