Sorsby syndrome: Report of a case representing the second reported family

Dismorfología y Genética ClínicaIn 1935, Sorsby [Br J Ophthalmol. 1935; 19:65-90] described a family with several affected individuals presenting with bilateral coloboma of macula, type B brachydactyly affecting hands and feet, and unilateral renal agenesis in one of its members. We describe a newborn girl presenting with the same pattern of congenital anomalies as the patients of the family originally described by Sorsby (OMIM 120400). However, the current case has as additional findings a single umbilical artery, and an anomaly of pulmonary vascularization consisting in: a ring in the lower right lobar artery and sequestration of the lower right lung lobe. Therefore, despite that our patient adds new clinical variability, it is not possible to disregard the diagnosis of Sorsby syndrome, because such clinical variability was also observed in the affected members of the original family described by Sorsby and some individuals of the next generations of the same family, according to the report by Thompson and Baraitser [J Med Genet. 1988; 25:313-321]. Based on the observed genealogy pattern of affected members in the only family published, it is considered that this syndrome is due to an autosomal dominant gene. The baby described here, is the first case in the family. She had a normal karyotype (~850 bands) and the subtelomeric Multi-FISH was also normal. Her father was 39 years old and, therefore, an age-related new mutation could be evaluated. The frequency of Sorsby syndrome is unknown, since only the original family has been published so far. However, as the case described here is part of the ECEMC Registry, we can estimate that its frequency is at least 1:2,750,000 newborn infants. We consider that, even in the “molecular era”, it remains important to clinically describe those extremely rare syndromes, in order to define their characteristics and clinical expressions. These aspects are essential to define the prognosis, clinical management and information to the family, and can help also to determine the gene(s) or pathogenetic pathways involved in their origin.N

Síndrome de Sorsby: descripción de un caso que representa la segunda familia descrita / Sorsby syndrome: Report of a case representing the second reported family.

In 1935, Sorsby [Br J Ophthalmol. 1935; 19:65-90] described a family with several affected individuals presenting with bilateral coloboma of macula, type B brachydactyly affecting hands and feet, and unilateral renal agenesis in one of its members. We describe a newborn girl presenting with the same pattern of congenital anomalies as the patients of the family originally described by Sorsby (OMIM 120400). However, the current case has as additional findings a single umbilical artery, and an anomaly of pulmonary vascularization consisting in: a ring in the lower right lobar artery and sequestration of the lower right lung lobe. Therefore, despite that our patient adds new clinical variability, it is not possible to disregard the diagnosis of Sorsby syndrome, because such clinical variability was also observed in the affected members of the original family described by Sorsby and some individuals of the next generations of the same family, according to the report by Thompson and Baraitser [J Med Genet. 1988; 25:313-321]. Based on the observed genealogy pattern of affected members in the only family published, it is considered that this syndrome is due to an autosomal dominant gene. The baby described here, is the first case in the family. She had a normal karyotype (~850 bands) and the subtelomeric Multi-FISH was also normal. Her father was 39 years old and, therefore, an age-related new mutation could be evaluated. The frequency of Sorsby syndrome is unknown, since only the original family has been published so far. However, as the case described here is part of the ECEMC Registry, we can estimate that its frequency is at least 1:2,750,000 newborn infants. We consider that, even in the “molecular era”, it remains important to clinically describe those extremely rare syndromes, in order to define their characteristics and clinical expressions. These aspects are essential to define the prognosis, clinical management and information to the family, and can help also to determine the gene(s) or pathogenetic pathways involved in their origin

Clinical manifestations of intermediate allele carriers in Huntington disease

Objective: There is controversy about the clinical consequences of intermediate alleles (IAs) in Huntington disease (HD). The main objective of this study was to establish the clinical manifestations of IA carriers for a prospective, international, European HD registry. Methods: We assessed a cohort of participants at risk with <36 CAG repeats of the huntingtin (HTT) gene. Outcome measures were the Unified Huntington's Disease Rating Scale (UHDRS) motor, cognitive, and behavior domains, Total Functional Capacity (TFC), and quality of life (Short Form-36 [SF-36]). This cohort was subdivided into IA carriers (27-35 CAG) and controls (<27 CAG) and younger vs older participants. IA carriers and controls were compared for sociodemographic, environmental, and outcome measures. We used regression analysis to estimate the association of age and CAG repeats on the UHDRS scores. Results: Of 12,190 participants, 657 (5.38%) with <36 CAG repeats were identified: 76 IA carriers (11.56%) and 581 controls (88.44%). After correcting for multiple comparisons, at baseline, we found no significant differences between IA carriers and controls for total UHDRS motor, SF-36, behavioral, cognitive, or TFC scores. However, older participants with IAs had higher chorea scores compared to controls (p 0.001). Linear regression analysis showed that aging was the most contributing factor to increased UHDRS motor scores (p 0.002). On the other hand, 1-year follow-up data analysis showed IA carriers had greater cognitive decline compared to controls (p 0.002). Conclusions: Although aging worsened the UHDRS scores independently of the genetic status, IAs might confer a late-onset abnormal motor and cognitive phenotype. These results might have important implications for genetic counseling. ClinicalTrials.gov identifier: NCT01590589

Clinical and genetic characteristics of late-onset Huntington's disease

Background: The frequency of late-onset Huntington's disease (&gt;59 years) is assumed to be low and the clinical course milder. However, previous literature on late-onset disease is scarce and inconclusive. Objective: Our aim is to study clinical characteristics of late-onset compared to common-onset HD patients in a large cohort of HD patients from the Registry database. Methods: Participants with late- and common-onset (30–50 years)were compared for first clinical symptoms, disease progression, CAG repeat size and family history. Participants with a missing CAG repeat size, a repeat size of ≤35 or a UHDRS motor score of ≤5 were excluded. Results: Of 6007 eligible participants, 687 had late-onset (11.4%) and 3216 (53.5%) common-onset HD. Late-onset (n = 577) had significantly more gait and balance problems as first symptom compared to common-onset (n = 2408) (P &lt;.001). Overall motor and cognitive performance (P &lt;.001) were worse, however only disease motor progression was slower (coefficient, −0.58; SE 0.16; P &lt;.001) compared to the common-onset group. Repeat size was significantly lower in the late-onset (n = 40.8; SD 1.6) compared to common-onset (n = 44.4; SD 2.8) (P &lt;.001). Fewer late-onset patients (n = 451) had a positive family history compared to common-onset (n = 2940) (P &lt;.001). Conclusions: Late-onset patients present more frequently with gait and balance problems as first symptom, and disease progression is not milder compared to common-onset HD patients apart from motor progression. The family history is likely to be negative, which might make diagnosing HD more difficult in this population. However, the balance and gait problems might be helpful in diagnosing HD in elderly patients