#620237
Table of Contents
A number sign (#) is used with this entry because of evidence that autosomal recessive intellectual developmental disorder-78 (MRT78) is caused by homozygous or compound heterozygous mutation in the WDR11 gene (606417) on chromosome 10q26.
Autosomal recessive intellectual developmental disorder-78 (MRT78) is a neurodevelopmental disorder characterized by impaired intellectual development that is usually mild, but shows variable severity. Affected individuals have microcephaly and mild short stature. Additional features may include ocular abnormalities and mild skeletal defects (Haag et al., 2021).
Haag et al. (2021) reported 6 patients from 3 unrelated families of various ethnic origins (from Syria, Singapore, and Kuwait) with variably impaired intellectual development, microcephaly, and mild short stature. Three patients from families A and B ranged from 8 to 12 years of age, whereas 3 affected sibs in family C were adults between 26 and 30 years of age. In all but 1 patient, intellectual disability was mild: 1 patient from family A had an IQ of 66, and 2 patients from family C were able to attend special schooling and work or volunteer in their communities. The most severely affected patient (family C) had no meaningful speech and needed to be fed at 30 years of age. Head circumference fell as low as -4.93 SD, although 2 of the older individuals showed improvement in head size over time (-3 to -4 SD as a child to -2 to -3 as adults). Brain imaging was normal in 3 patients who were studied. Additional features observed in 1 or 2 patients included skin hypopigmentation, myopia, strabismus, exotropia, optic neuropathy, high-arched palate, microretrognathia, narrow chest, kyphoscoliosis, fifth finger clinodactyly, and brachydactyly. One patient had mild sensorineural hearing loss. None had evidence of pituitary or endocrine abnormalities.
The transmission pattern of MRT78 in the families reported by Haag et al. (2021) was consistent with autosomal recessive inheritance.
In 6 patients from 3 unrelated families with MRT78, Haag et al. (2021) identified homozygous or compound heterozygous loss-of-function mutations in the WDR11 gene (606417.0004-606417.0007). The mutations, which were found by exome sequencing and confirmed by Sanger sequencing, segregated with the disorder in all 3 families. Western blot analysis of fibroblasts from 1 of the patients demonstrated complete absence of the WDR11 protein. Functional studies of the variants were not performed.
Haag, N., Tan, E.-C., Begemann, M., Buschmann, L., Kraft, F., Holschbach, P., Lai, A. H. M., Brett, M., Mochida, G. H., DiTroia, S., Pais, L., Neil, J. E., Al-Saffar, M., Bastaki, L., Walsh, C. A., Kurth, I., Knopp, C. Biallelic loss-of-function variants in WDR11 are associated with microcephaly and intellectual disability. Europ. J. Hum. Genet. 29: 1663-1668, 2021. [PubMed: 34413497, images, related citations] [Full Text]
Location | Phenotype |
Phenotype MIM number |
Inheritance |
Phenotype mapping key |
Gene/Locus |
Gene/Locus MIM number |
---|---|---|---|---|---|---|
10q26.12 | Intellectual developmental disorder, autosomal recessive 78 | 620237 | Autosomal recessive | 3 | WDR11 | 606417 |
A number sign (#) is used with this entry because of evidence that autosomal recessive intellectual developmental disorder-78 (MRT78) is caused by homozygous or compound heterozygous mutation in the WDR11 gene (606417) on chromosome 10q26.
Autosomal recessive intellectual developmental disorder-78 (MRT78) is a neurodevelopmental disorder characterized by impaired intellectual development that is usually mild, but shows variable severity. Affected individuals have microcephaly and mild short stature. Additional features may include ocular abnormalities and mild skeletal defects (Haag et al., 2021).
Haag et al. (2021) reported 6 patients from 3 unrelated families of various ethnic origins (from Syria, Singapore, and Kuwait) with variably impaired intellectual development, microcephaly, and mild short stature. Three patients from families A and B ranged from 8 to 12 years of age, whereas 3 affected sibs in family C were adults between 26 and 30 years of age. In all but 1 patient, intellectual disability was mild: 1 patient from family A had an IQ of 66, and 2 patients from family C were able to attend special schooling and work or volunteer in their communities. The most severely affected patient (family C) had no meaningful speech and needed to be fed at 30 years of age. Head circumference fell as low as -4.93 SD, although 2 of the older individuals showed improvement in head size over time (-3 to -4 SD as a child to -2 to -3 as adults). Brain imaging was normal in 3 patients who were studied. Additional features observed in 1 or 2 patients included skin hypopigmentation, myopia, strabismus, exotropia, optic neuropathy, high-arched palate, microretrognathia, narrow chest, kyphoscoliosis, fifth finger clinodactyly, and brachydactyly. One patient had mild sensorineural hearing loss. None had evidence of pituitary or endocrine abnormalities.
The transmission pattern of MRT78 in the families reported by Haag et al. (2021) was consistent with autosomal recessive inheritance.
In 6 patients from 3 unrelated families with MRT78, Haag et al. (2021) identified homozygous or compound heterozygous loss-of-function mutations in the WDR11 gene (606417.0004-606417.0007). The mutations, which were found by exome sequencing and confirmed by Sanger sequencing, segregated with the disorder in all 3 families. Western blot analysis of fibroblasts from 1 of the patients demonstrated complete absence of the WDR11 protein. Functional studies of the variants were not performed.
Haag, N., Tan, E.-C., Begemann, M., Buschmann, L., Kraft, F., Holschbach, P., Lai, A. H. M., Brett, M., Mochida, G. H., DiTroia, S., Pais, L., Neil, J. E., Al-Saffar, M., Bastaki, L., Walsh, C. A., Kurth, I., Knopp, C. Biallelic loss-of-function variants in WDR11 are associated with microcephaly and intellectual disability. Europ. J. Hum. Genet. 29: 1663-1668, 2021. [PubMed: 34413497] [Full Text: https://doi.org/10.1038/s41431-021-00943-5]
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