Autosomal recessive Melnick-Needles syndrome or ter Haar syndrome? Report of a patient and reappraisal of an earlier report.

We report on a patient with congenital glaucoma, brachycephaly with flat occiput, large anterior fontanel, hypertelorism, anteverted nostrils, thoracolumbar kyphosis, prominent coccyx with skin fold, short hands and feet, flexion deformity of fingers, and clubfeet. He had a double-outlet right ventricle with ventricular septal defect, and severe tricuspid insufficiency. Mild skeletal changes included short tubular bones, absence of distal phalanges of toes, caliber variation of ribs, and scalloping of the anterior surface of vertebrae. The patient died at age 21 months. He belongs to the same extended family as 3 similarly affected patients, previously described by ter Haar et al. [1982: Am J Med Genet 13:469-477] as representing an autosomal recessive form of Melnick-Needles syndrome. We believe this diagnosis is no longer tenable. After having reviewed the relevant literature, we conclude that most probably we are dealing with a new autosomal recessive syndrome. We propose to name this entity ter Haar syndrome.

Influence of sex of the transmitting parent as well as of parental allele size on the CTG expansion in myotonic dystrophy (DM).

In patients with myotonic dystrophy (DM), the severity of clinical signs is correlated with the length of a (CTG)n trinucleotide repeat sequence. This sequence tends to expand in subsequent generations. In order to examine the kinetics of this process and, in particular, the influence of the mutant-allele size and the sex of the transmitting parent, we have studied (CTG)n repeat lengths in the offspring of 38 healthy carriers with small mutations (less than 100 CTG trinucleotides, mean length [CTG]67). In these studies, we found a weakly positive correlation between the size of the mutation in the carrier parents and that in their offspring. Furthermore, we observed that, in the offspring of male transmitters, repeat lengths exceeding 100 CTG trinucleotides were much more frequent than in the offspring of carrier females (48 [92%] of 52 vs. 7 [44%] of 16, P = .0002). Similarly, in genealogical studies performed in 38 Dutch DM kindreds, an excess of nonmanifesting male transmitters was noted, which was most conspicuous in the generation immediately preceding that with phenotypic expression of DM. Thus, two separate lines of evidence suggest that the sex of the transmitting parent is an important factor that determines DM allele size in the offspring. On the basis of our data, we estimate that when both parents are asymptomatic, the odds are approximately 2:1 that the father carries the DM mutation. Because expansion of the CTG repeat is more rapid with male transmission, negative selection during spermatogenesis may be required to explain the exclusive maternal inheritance of severe congenital onset DM.

Bloom's syndrome in two Dutch families.

The clinical and cytogenetic data are presented of four children with Bloom's syndrome, who belong to two unrelated Dutch families. The patients showed, in varying degrees, the clinical features most characteristic of the syndrome: stunted growth; telangiectatic facial erythema; sun-sensitivity of the skin; and decreased immuno-competence. In one child the skin lesions were only minor and the diagnosis would probably not have been made if her sib had not been recognized as having Bloom's syndrome. The cytogenetic characteristics of the syndrome were present in all patients. Each showed a high number of chromosomal aberrations and numerous sister-chromatid exchanges per cell.